I also have the same problem. I did:

apt-get install libgcc1
apt-get install libc6

After that my calendar permanently crashed. I removed the dashboard widget but still got the message. I had to uninstall the calendar to get rid of the message. The good thing is: you can reinstall the calendar. The bad thing is: Then you will get the error message again. I have read a few posts saying that importing all the your calendar events might fix the problem but I didn´t have the time to figure out how (...with a crashing calendar).
Seems like libc6 still has some incompatibilities. libc6 resides inside the dev-repository, right? That might explain a lot.

UPDATE:
I just installed the OS upgrade via Nokia Software Updater which virtually killed everything I had previously installed. Calendar is working again and I haven´t got any error messages so far. What bugs me is that I have to reinstall every single package now. But there are many ways to cover that.