Re: White Screen instead of desktop in 10.10 (Radeon 7500 card)
To both of you ...
If you're going to upgrade to pre-release versions of Ubuntu, then you need to keep a close check on the appropriate Development forum -- which is where these kinds of posts (and answers) are supposed to go.
As a matter of fact, if you check the Maverick Development forum and do a search on ATI, you will find a post dealing with radeon-driver problems that also contains a fix.
So, please go to THAT forum with your questions, not here.
And in the future, please post your Beta-related questions to the proper Development forum. You'll get answers a lot quicker that way.
Ubuntu 15.04 Mate, Mint 17.1; MS Win 8.1, Win10 TP.
Will not respond to PM requests for support -- use the forums.