I discovered a very specific issue with modal Inspectors in Windows 7 systems running Outlook 2007. I'm developing an addin that places a ribbon button and UserControl (in the form of a taskPane) into the email-compose window.
The issue is: with that specific setup, (with Outlook 2007 already running) when the user attempts to launch an email-compose window externally (this can be through 'send via email' in Adobe Reader or many other applications).
The TaskPane that appears appended to the right-side of the form has a semi-random chance to not draw and simply appear blank.
I have prepared a sample solution that trims down all the unnecessary fat, if you look in the bin>debug folder, there is a ready-to-run sample to demonstrate the issue
http://www.mediafire.com/file/ctmsbba09n6u0vp/MissingPaneExample.zip