Random Restarts after Citrx and Firmware Upgrade

[dheida]

We upgraded to Citrix Presentation Server 4 this last Saturday and since Tuesday one of the servers has been restarting at random; once today, three times last night, no pattern. Just a little bit ago a different Citrix server restarted. They are on HP Proliant DL380's running updated Windows 2000. Nothing in the Event Viewers. Also, on Sunday, we updated all of the HP servers to the latest firmware. Right away we thought this to be the cause but we also updated firmware on six other non-Citrix DL380's with no restarts, yet. Do you think the cause is more likely Citrix or Firmware? (And hopefully I won't get too many biased answers since this is the hardware forum.)