Make sure that the data source is accessible to all other machines, e.g. if you used an ODBC DSN as the report's data source, make sure the same DSN exists on any workstation that you plan on running the report from.
If that's not your issue, please, as k stated, post your connectivity. Also, the Crystal Print Engine method you're using in VB (RDC, OCX, API, etc.).
-dave