I missed adding the same exclusion test in CXTPTabWorkspace::LButtonDown around the for loop, this disables dragging of a tab by starting in the button area:

CRect rc;         GetClientRect(&rc);     rc.right -= m_nButtonWidth;         if (rc.PtInRect(point))     {         for (int i = 0; i < m_arrTab.GetSize(); i++)         {              if (m_arrTab.rcItem.PtInRect(point))              {                  for (int j = 0; j < m_arrTab.GetSize(); j++)                      m_lstRects.Add(m_arrTab[j].rcItem);                                   m_nItemTracking = i;                  SetCapture();                  Invalidate(FALSE);                  break;              }         }     }     CWnd::OnLButtonDown(nFlags, point); }

The CXTPTabWorkspace control does not exclude the button region from the tab hit test. This makes a partial tab displayed under the button area show as Hovering over when the mouse is in the button area. Also allows you to Drag a tab when starting the drag in the button area.

Solution:

Add protected int m_nButtonWidth member to CXTPTabWorkspace. In paint manager DrawTabControlXXXXX functions at the top of each function clear this variable to 0 and after caclulating the nButtonWidth local variable assign the value to pCtrlTab->m_nButtonWidth. In every style of paint manager DrawTabControlXXXX.

Change HitTest to exclude that area from a valid tab button area.

int CXTPTabWorkspace::HitTest(CPoint point) {     CRect rc;     GetClientRect(&rc);     rc.right -= m_nButtonWidth;     if (rc.PtInRect(point))     {         for (int i = 0; i < m_arrTab.GetSize(); i++)         {              if (m_arrTab.rcItem.PtInRect(point))              {                  return i;              }         }     }     return -1; }

Add the same wrapper in CXTPTabWorkspace::OnMouseMove

void CXTPTabWorkspace::OnMouseMove(UINT nFlags, CPoint point) {     CRect rc;     GetClientRect(&rc);     rc.right -= m_nButtonWidth;     if (rc.PtInRect(point))     {         if (m_nItemTracking != -1)         {            . . .         }     }     else     {         if (TRUE)//if (m_dwStyle & CBRS_ALIGN_TOP)         {              m_btnClose.CheckForMouseOver(this, point);              m_btnLeft.CheckForMouseOver(this, point);              m_btnRight.CheckForMouseOver(this, point);         }     }     HighlightFocused();     CWnd::OnMouseMove(nFlags, point); }

The tabs will stop seeing the mouse in the button area as over the tab. Someone who is more familiar with the toolkit should review this fix. I could have easily missed something critical.