Here is the Top 10 external bugs of Flash Runtime in Jan 2012, which is order by incoming votes in Adobe bug base:
1. Mac OSX Player Issue: kernel: IOSurface: buffer allocation size is zero
The log file (kernel.log) gets flooded with "kernel: IOSurface: buffer allocation size is zero." messages.
https://bugbase.adobe.com/index.cfm?event=bug&id=3077658
2. iOS and Android Native Scroll
https://bugbase.adobe.com/index.cfm?event=bug&id=2958123
3. Flash 11 showing black shapes in BBC iplayer
https://bugbase.adobe.com/index.cfm?event=bug&id=3008910
4. Video not working correctly for Air 3.1.0.556 on Android ICS
https://bugbase.adobe.com/index.cfm?event=bug&id=3100560
[……]