I had ubuntu 9.10 I upgraded to 10.04 after solving some problems (freeze at boot).

Since then, I don't have the ubuntu's logo showing up when I boot, but a purple screen with some blinking pixels. I didn't care much about it... but today my computer took too long at that screen (normally it was just 1/4 second, but today it was like a minute..). And it happened like 4 or 5 times in a row (Only at the 5th time I realised that it was not freezing up, but it simply would took more time)

After a reboot, it is again 1/4 second of purple screen but I don't want this problem to return.. so I want to get rid of the purple screen (I think it is an indicator of the problem)

Well, I already installed the graphic drivers (going to system > admnistration > hardware drivers). But it didn't solve anything. (I don't know if it is even related)

I searched in google, found something old (2006) and I think it maybe has some relation with my problems .. http://ubuntuforums.org/archive/index.php/t-294692.html

But couldn't understand the conversation (i'm a linux novice)

Sorry for my horrible english.. I would appreciate any help!

My hardware: ATI Mobility Radeon 4650 HD P7450 2.13Ghz Core 2 Duo