I'm a new IM user having big problems getting IM to run without freezing (reporting "Not responding" ).
 
The problem first started when I tried to import some very simple obj objects. IM showed the hourglass, and the title bar shows "Not responding" (actually "Svarer ikke", which is because my XP is Norwegian).
I tried many times with different objects, but no luck. The objects never shows up in the scene neither, and the screen isn't redrawn completely after showing the File dialog.
Then I tried importing some of the objects supplied with IM. They did show up and I was able to "pin" them into place, but after a while IM freezes again (Task manager always shows 0% CPU for IM then).
Now this even happens when I add some of the internal primitives, like a cube.  
 
Is this a known problem?
 
I'm using XP Pro with all the latest service packs and updates installed.
I have an Athlon 3000+ with 1.5GB RAM and a Radeon 9800 Pro video card with the newest Cadalyst drivers.  

I got some help from Realviz on this problem - they suggested that it might be a driver problem.
Catalyst had just released new drivers a couple of days ago, and after installing those everything works just fine :-)