GDI+ Dispose Error?

I'm using the actipro docking system within my application and recently it began throwing a GDI+ error on application close which appears to be coming from actipro, but I'm not 100% sure of that yet... Here's the exact exception and a stack trace. Any ideas?

Additional information: Internal error: GDI+ is not properly initialized.

Unhandled Exception: System.Runtime.InteropServices.ExternalException: Internal error: GDI+ is not properly initialized.
at System.Drawing.Graphics.FromHwndInternal(IntPtr hwnd)
at System.Windows.Forms.Control.CreateGraphicsInternal()
at System.Windows.Forms.Control.CreateGraphics()
at ActiproSoftware.WinUICore.UIControl.UpdateLayout()
at ActiproSoftware.WinUICore.UIControl.Invalidate(InvalidationLevels levels, InvalidationTypes types)
at ActiproSoftware.WinUICore.UIControl.OnLayout(LayoutEventArgs e)
at System.Windows.Forms.Control.PerformLayout(Control affectedControl, String affectedProperty)
at System.Windows.Forms.Control.SetVisibleCore(Boolean value)
at System.Windows.Forms.Control.set_Visible(Boolean value)
at ActiproSoftware.UIStudio.Dock.ToolWindowContainer.?(ToolWindow )
at ActiproSoftware.UIStudio.Dock.DockManager.?(TabbedMdiWindow[] )
at ActiproSoftware.UIStudio.Dock.DockManager.?(TabbedMdiWindow[] , Boolean )
at ActiproSoftware.UIStudio.Dock.ToolWindow.Dispose(Boolean disposing)
at System.ComponentModel.Component.Finalize()The program '[2376] WorkEnvironment.exe' has exited with code 0 (0x0)