I think I'd be inclined to run the SQL profiler t see what Sage is asking for when the Supplier list is called, then run the profiler again then you use the supplier lookup. That'll give you the SQL request & from that you can work out why the expected data isn't being returned, i.e. some missing related data. That's quite a lengthy task do though. I take it you have tried checking the database, rebuilding the indexes just incase it's something related to that?

I think I'd be inclined to run the SQL profiler t see what Sage is asking for when the Supplier list is called, then run the profiler again then you use the supplier lookup. That'll give you the SQL request & from that you can work out why the expected data isn't being returned, i.e. some missing related data. That's quite a lengthy task do though. I take it you have tried checking the database, rebuilding the indexes just incase it's something related to that?

Database?  Nobody told me anything about a database!

Unless you are using Sage 200 Standard or the Education variant I'd suggest talking to your business partner