Thanks for the answer.
I have 2 more questions:
1) For our new customers we are going to offer VMWare vSphere PowerCLI 5.0 build 435427 together with ESXi 5.0.0 Update 1. Can you check if the fix is available in those builds or we have to take PowerCLI5.1 R2?
2) Even with ESX4 and PowerCLI 4.0 U1 build 208462 we do not experience Powershell crash on all Windows XP PCs. Can you point us to what can be changed on PC to prevent this from happening? I tried to change locale,ip configuration but that did not help.