No, I've never experienced that problem myself.
I work on two screens - Floor plan on the left, 3D view and navigator on the right, so I don't have the need to manually switch between them.
I haven't had any experience of macs so maybe someone else out there may have come across the problem.
If it becomes very annoying try reinstalling perhaps, or even have a word with your AC reseller - Applecore or Bite.
Edit -
It looks like it happens to other people too. See the last post by cadaron - on a mac too (He's not your colleague you mentioned before is it?
)
http://archicad-talk.graphisoft.com/viewtopic.php?t=17650&postdays=0&postorder=asc&&start=10
Edit again -
Ahh, he
is
your colleague (I looked on his web site.) My suggestion above was actually a joke!!
I'm obviously psychic!!