My application works well standalone. As additional users (2-3) run the application (which resides on the server) performance degrades. I'm using parameterized views. Earlier versions of my app exhibited no such behavior. The largest table has 1,285,563 records. Where should I begin to look?

What changed? When you say that earlier versions had no trouble, what was the difference between the versions?

What are the symptoms of "bogging down"? Server disk thrashing? Network activity? Is it general data retrieval, (slow refresh of browses of read-only data)? Or does updating records take much longer than they used to?

Just FYI because it's not an direct answer to your question, for optimum performance, I recommend:
-- local copies of the application
-- local .DBC files (remote views created programmatically then cached)
-- SQL server for data storage.

- Colin