Serious clock problem

[FTALOVER <fta@satelcom.qc.ca>]

Hi all,

I'm running VMW ESXi 3i (3.5.0) on an 4 CPUs DELL Poweredge 1950.  This 
machine is  hosting 8 virtual machines, 5 running Etch and 3 running 
Lenny. All guests were running fine until I upgraded the kernel to 
linux-image-2.6.26-2-686_2.6.26-19 in the 3 boxes running Lenny.  Now 
those boxes are repeatedly freezing because the system clock seems to 
stall. Forcing the kernel to use acpi_pm as clocksource instead of TSC 
and disabling TSC doesn't seems to help. So, does anybody have any 
suggestion  on how to fix this?

Thanks

Eric L.