I have a few different virtualbox installs all on Ubuntu hosts. One thing I have noticed which seems strange is that copyt and paste definitely works but there is some strangeness from a Linux/Ubuntu host to a XP guest. If I copy a set of numbers from gedit or linux firefox and paste it into my XP guest, it all works great! Yay! But if I select a second block of text or numbers on Linux and then try to paste it into notepad, the text that appears is from the first copy and paste episode. I have to close out both applications and then redo the copy and paste. It seems to be stuck on the first cut and paste value and the second and subsequent copy and pastes do not include the second set of data I selected and copied.
I have the guest additions installed and I've tried copying in both directions and it all works. But it only seems to work once.