VirtualBox 3.0 crashes hard on RHEL 5.3 64-bit

[mbay2002]

I just upgraded to VirtualBox 3.0 on a RHEL 5.3 machine 64-bit, and when I try to start it up, it brings the whole machine down (hard re-boot). I'm going to revert to 2.2.4 for now... the only thing I can find are a few lines in /var/log/messages:

Jul 6 12:19:20 lx57 kernel: VBoxDrv: dbg - g_abExecMemory=ffffffff88e6db00
Jul 6 12:19:20 lx57 kernel: vboxdrv: fAsync=0 offMin=0x73f offMax=0x1593
Jul 6 12:19:20 lx57 kernel: vboxdrv: TSC mode is 'synchronous', kernel timer mode is 'normal'.
Jul 6 12:19:20 lx57 kernel: VBoxNetFlt: dbg - g_abExecMemory=ffffffff890a9ae0


Any ideas?
FWIW, I also upgraded a Mac host (Ubuntu guest) to 3.0 , and though it works, the performance is noticeably slower than 2.2.4.

[agent_paul]

I've also got a problem with RHEL 5.3 64bit and Vbox 3.0.

instead of hard crashing my guest machine crashes and displays a fuzzy like screen then utilizes 100% CPU