a few Citrix citrix servers which were earlier cloned and were working fine almost for six months started shutting down unexpectedly. dell support updateddrivers for raid controllers, vga, nic. dell say its not a hardware issue. so its an os or a citrix issue. only change that was donw to the servers was that a few microsoft updates and a cirix rollup packages were installed. no obvious time/date patter for the unexpected shutdown. only pattern that the print jobs are running before he unexpected shutdown. hp 4250 pcl6 in particular.