Common problem in many cm7 roms is the "492 error".
The popular method involves clearing data of google framework, play store and clear cache& dalvik cache....
For ppl (like me) who were unsuccessful in solving the error, here's an alternative method.
What i observed was - when i encountered a 492 error in Google play store, in recovery too i found this - "E: can't open/cache/recovery/last_log
So here's what you should do -
1. Backup data in recovery
2. Wipe everything
3. Advanced /Reboot recovery
4. Restore everything
Now u can install apps without any errors (also u won't find - E:Can't open/..... Error in recovery too). Worked for me in New experience rom. Plz report