In a mixed thin client / fat client environment (Citrix esp.) where the drives on the terminal servers have been remapped for whatever reason (M: N: O: quite common) certain issues can arise with Office Integration both in and out of Citrix.
Even running asupdate on the fat client to install TAM generates an error in this situation - this is due to the fact that TAM has certain global settings that wreak havoc in this somewhat mismatched environments. It may become necessary to create some substitute drive letters on the fat clients:
subst m: c:\
works in our environment where the Citrix server have an m: system drive and Office apps are installed on M: as well.