diff --git a/backend/app/models/task_comment.py b/backend/app/models/task_comment.py
index 3a11516..0a1423a 100644
--- a/backend/app/models/task_comment.py
+++ b/backend/app/models/task_comment.py
@@ -1,4 +1,4 @@
-from sqlalchemy import Text, Integer, ForeignKey, func
+from sqlalchemy import Text, Integer, ForeignKey
 from sqlalchemy.orm import Mapped, mapped_column, relationship as sa_relationship
 from datetime import datetime
 from app.database import Base
@@ -12,7 +12,7 @@ class TaskComment(Base):
         Integer, ForeignKey("project_tasks.id", ondelete="CASCADE"), nullable=False, index=True
     )
     content: Mapped[str] = mapped_column(Text, nullable=False)
-    created_at: Mapped[datetime] = mapped_column(server_default=func.now())
+    created_at: Mapped[datetime] = mapped_column(default=datetime.now)
 
     # Relationships
     task: Mapped["ProjectTask"] = sa_relationship(back_populates="comments")
diff --git a/backend/app/routers/events.py b/backend/app/routers/events.py
index a3a655c..21c2e92 100644
--- a/backend/app/routers/events.py
+++ b/backend/app/routers/events.py
@@ -287,7 +287,7 @@ async def update_event(
 
     start = update_data.get("start_datetime", event.start_datetime)
     end_dt = update_data.get("end_datetime", event.end_datetime)
-    if end_dt < start:
+    if end_dt is not None and end_dt < start:
         raise HTTPException(status_code=400, detail="End datetime must be after start datetime")
 
     if scope == "this":
@@ -316,6 +316,7 @@ async def update_event(
                 delete(CalendarEvent).where(
                     CalendarEvent.parent_event_id == parent_id,
                     CalendarEvent.original_start >= this_original_start,
+                    CalendarEvent.id != event_id,
                 )
             )
 
diff --git a/frontend/src/components/dashboard/UpcomingWidget.tsx b/frontend/src/components/dashboard/UpcomingWidget.tsx
index 41c3d95..e09ff81 100644
--- a/frontend/src/components/dashboard/UpcomingWidget.tsx
+++ b/frontend/src/components/dashboard/UpcomingWidget.tsx
@@ -57,10 +57,11 @@ export default function UpcomingWidget({ items, days = 7 }: UpcomingWidgetProps)
                       {config.label}
                     </span>
                     <span className={cn(
-                      'text-[9px] font-semibold px-1.5 py-0.5 rounded shrink-0 w-10 text-center',
+                      'text-[9px] font-semibold px-1.5 py-0.5 rounded shrink-0 w-14 text-center',
                       item.priority === 'high' ? 'bg-red-500/10 text-red-400' :
                       item.priority === 'medium' ? 'bg-yellow-500/10 text-yellow-400' :
                       item.priority === 'low' ? 'bg-green-500/10 text-green-400' :
+                      item.priority === 'none' ? 'bg-gray-500/10 text-gray-400' :
                       'invisible'
                     )}>
                       {item.priority || ''}
diff --git a/frontend/src/components/projects/ProjectDetail.tsx b/frontend/src/components/projects/ProjectDetail.tsx
index f7f5989..f89de7f 100644
--- a/frontend/src/components/projects/ProjectDetail.tsx
+++ b/frontend/src/components/projects/ProjectDetail.tsx
@@ -575,6 +575,7 @@ export default function ProjectDetail() {
                   onEdit={(task) => openTaskForm(task, null)}
                   onDelete={handleDeleteTask}
                   onAddSubtask={(parentId) => openTaskForm(null, parentId)}
+                  onClose={() => setSelectedTaskId(null)}
                 />
               </div>
             </div>
@@ -603,6 +604,7 @@ export default function ProjectDetail() {
                 onEdit={(task) => openTaskForm(task, null)}
                 onDelete={handleDeleteTask}
                 onAddSubtask={(parentId) => openTaskForm(null, parentId)}
+                onClose={() => setSelectedTaskId(null)}
               />
             </div>
           </div>
diff --git a/frontend/src/components/projects/TaskDetailPanel.tsx b/frontend/src/components/projects/TaskDetailPanel.tsx
index b7c09cd..17f8190 100644
--- a/frontend/src/components/projects/TaskDetailPanel.tsx
+++ b/frontend/src/components/projects/TaskDetailPanel.tsx
@@ -4,7 +4,7 @@ import { toast } from 'sonner';
 import { format, formatDistanceToNow, parseISO } from 'date-fns';
 import {
   Pencil, Trash2, Plus, MessageSquare, ClipboardList,
-  Calendar, User, Flag, Activity, Send,
+  Calendar, User, Flag, Activity, Send, X,
 } from 'lucide-react';
 import api, { getErrorMessage } from '@/lib/api';
 import type { ProjectTask, TaskComment, Person } from '@/types';
@@ -37,6 +37,7 @@ interface TaskDetailPanelProps {
   onEdit: (task: ProjectTask) => void;
   onDelete: (taskId: number) => void;
   onAddSubtask: (parentId: number) => void;
+  onClose?: () => void;
 }
 
 export default function TaskDetailPanel({
@@ -45,6 +46,7 @@ export default function TaskDetailPanel({
   onEdit,
   onDelete,
   onAddSubtask,
+  onClose,
 }: TaskDetailPanelProps) {
   const queryClient = useQueryClient();
   const [commentText, setCommentText] = useState('');
@@ -145,6 +147,17 @@ export default function TaskDetailPanel({
             >
               <Trash2 className="h-3.5 w-3.5" />
             </Button>
+            {onClose && (
+              <Button
+                variant="ghost"
+                size="icon"
+                className="h-7 w-7"
+                onClick={onClose}
+                title="Close panel"
+              >
+                <X className="h-3.5 w-3.5" />
+              </Button>
+            )}
           </div>
         </div>
       </div>
@@ -222,15 +235,17 @@ export default function TaskDetailPanel({
                 </span>
               )}
             </h4>
-            <Button
-              variant="ghost"
-              size="sm"
-              className="h-6 text-xs px-2"
-              onClick={() => onAddSubtask(task.id)}
-            >
-              <Plus className="h-3 w-3 mr-1" />
-              Add
-            </Button>
+            {!task.parent_task_id && (
+              <Button
+                variant="ghost"
+                size="sm"
+                className="h-6 text-xs px-2"
+                onClick={() => onAddSubtask(task.id)}
+              >
+                <Plus className="h-3 w-3 mr-1" />
+                Add
+              </Button>
+            )}
           </div>
           {task.subtasks.length > 0 ? (
             <div className="space-y-1">