ok, it works again.
Here is what I did:
- contacting apple support, ask them what to do. their advice:
- 1. create a new, fresh account to test if its a systemwide problem, or user specific
- 2. boot into safe mode once, and reboot system again
- 3. reset SMC/PRAM
- 4. reinstall keynote
- 5. install 10.7 combo update...
- I followed step 1 & 2: the problem was systemwide, and booting into safe mode did not help
- then I just tried to update keynote via the appstore to see if that would help. It did help, it seems all good again.
interesting that the support guy on the phone did not mention this first, but wanted to let me go through all kinds of steps - even though I told him EXACTLY what osX/keynote version I used, down to the build!