You must not click for install but check your permissions of the file! They must be rw-r--r--
I double checked everything and I have absolutely no clue what happens in your case. To be on the safe side, try following scenarios:
1.
- go to recovery, flash v2 again (maybe download again!)
- clear dalvik and cache, then advanced -> fix permissions
- reboot
or
2.
- uninstall calendar with titanium backup, be sure to remove update from market first!
- recovery, flash v1
- go to playstore, update - then uninstall update
- recovery, flash v2
- reboot
There is absolutely no reason why v1 works and v2 not if you flash correctly via CWM and correctly installed busybox in sbin. Otherwise I have no idea, sorry - the only thing would be, that v2 is incompatible with CM10 nightly for some reason, but as I changed only small portions of Calendar and use the original signature files, there shouldn't be any problem. Heard this the first time...
Is there any other user out there with the same problem as zopostyle?