Succesful boot 1 in 5 times

[idee]

I have been putting up with this problem for 3 months now, but it became worse after a recent clean install of 10.7.3 and it's now too frustrating to ignore. The issue: I can only boot into Lion successfully about 1 in 5 times. When I try to boot, the system will apparently randomly choose one of the following behaviours:

• a) Hang at the Gigabyte splash screen
  b) Restart itself after a few seconds at the Gigabyte splash screen
  c) Hang at the Apple logo, no spinny wheel
  d) Hang at the Apple logo, endlessly spinny wheel
  e) Hang at the Apple logo, spinny wheel that freezes after a while
  f) Hang at the Apple logo, spinny wheel and "no entry" symbol that appears after a while (new for 10.7.3!)
  g) Successfully boot into Lion, then freeze after up to a minute
  h) Successfully boot into Lion

Sometimes it can take me 10 minutes or more just to start up my Hack, but when it's started, it's fine. If it weren't for this one major problem my machine would be solid.

Can anyone help figure this out?

 

[powerpcg5]

Try replacing your 6850 with a 6870 card?

 

[idee]

Is that a known issue with the 6850?

 

[idee]

Bump -

I can now only boot with rBoot, and even then after about 10 tries. If anyone can help I'd be extremely grateful.