May be they are not optimized for ICS yet. This is the problem people will have when a brand new OS launches. I believe google tried to minimize the effort to make the apps compatible to ICS, but the developers have some responsibility here as well.
Do I also occasionally get a message unfortunately outlook stopped working also?
I had the same problem. But at the same time multiple other apps also stopped working so that made me think the problem was something else rather than the outlook app.I even updated the outlook app as well as all the other apps that weren't working but none of then would work.I then noticed that there was 2 copies of the outlook app. The original old one and the newer one that I installed (during my attemps to fix all the apps that stopped working).*I then deleted to old outlook app. Suddenly low and behold all the apps srarted working again and the outlook error message dissappear. Woot!This was my solution. Give it a try