After upgrade to 10.04 beta 2, can't log on (module is unknown)

[nasevz]

I upgraded from Carmic to Lucid beta 2, but after rebooting when I tried to log on I got message "module is unknown". The only way to get to the system is to boot to recovery and choose "Drop to root shell prompt".
Any idea how to fix this?

[utnubuuser]

As far as I know, upgrades are intended mainly between LTSs. Don't know if this is true anymore, but I read plenty of posts in the past stating that upgrading between releases is intended mostly for LTS-to-LTS, not so much the in-between releases.

[nasevz]

On the first page of Ubuntu there is download beta 2 link and the first thing I noticed following the link was Upgrading from Ubuntu 9.10 or Ubuntu 8.04 LTS . I hope I didn't make something that can't be repaired.

I saw very little posts mentioning "module is unknown" message and none of them had a real solution.