SQL Server 2000: Can't DROP VIEW?
Run SQL Profiler to identify who, where etc. You have various columns with hostname, ntusername etc that will allow you to see usage.

For example: is if just one client or user who notices? Are they running a different ADP?

The view call can be embedded in some Form properties too as the RecordSource for that form, or as the source for some control. It may not be in VBA. You'd have to write some VBA to iterate through the forms, controls and reports testing assorted properties.