Window "frames" remaining after sending mail [in Outlook]

Hello, got a bit of an odd problem, not sure if it's an outlook or a server issue but I'm suspecting outlook.
We're running terminal services with windows server 2008 and for the most part it's grand, but there's one user that has a bit of a problem.
When they send mail the mail gets sent no problem but about a quarter of the time the frame of the messgae remains. The border is there but the main text field is transparent. It'll stay there until it's closed.

It's not exactly mission critical but it's rather odd and I haven't been able to do anything about it so far

 

oh

those are two very good questions that I don't have answers to. It's tricky getting access to this machine and so far I've not been able to reproduce the issue on another users account