One of our clients wanted to start using the deployment of virtual machines with the customization wizard in VirtualCenter. For a strange reason this didn’t work. Probably the time of day wasn’t right for me, because I totally forgot the article about the customization problem.
If you change the path for the TEMP and TMP variables to store tempfiles on another location the customization fails. It looks like the process can’t copy the files to the desired location.
http://kb.vmware.com/kb/1005943
I know, it’s an old kb article, but perhaps it can save you time (and stupid looks from your collegues ;))