>We have a system with fairly large tables at some of our client sites.
>Reindexing the tables when they are on the same machine as the exe goes relatively quickly for the size of these tables. 30 minutes or less. When the same tables are placed out on the network, which is the most common scenario for most of our clients, reindexing can take as long as 3 hours.
>Does anyone have a clue as to what the slow down could be or what can be done to speed it up.

In addition to what Houston said, you can also build a DCOM server to handle this. The client system could implement a DCOM server on the machine where the data resides. The processing to reindex would take place "locally" with respect to the data. The client machine would need to periodically check a status flag on the DCOM server to see when it was done.