I am currently testing Ubuntu 9.04 Jaunty and when it upgraded 7.3 mesa
to 7.4 mesa my PC was freezeing, the fix was to downgrade back to 7.3
I am skeptical that 7.5 are going to fix this issue with intel945since they
only recently discovered that it was causing freezes with my Intel Mobile GM965/GL960 Integrated Graphics Controller
[Bug 359392] Re: https://bugs.launchpad.net/bugs/359392
So far my Lenovo R61e has not freezed with 7.3 mesa, I am continuing
to monitor its performance.