ROSA Forum

After install I rebooted and I get the Rosa screen then purple lines and it stays that way. Video Card ATI Radeon 4870.

Try start Rosa in "(Safe mode)".

Are you sure that it was right after first rebooting? On live-mode ROSA uses open source Radeon drivers, so if you had installed proprietary driver (fglrx) after installing ROSA, it would need some tweakings/global repair.