I have a long query in my DLL app and i decided to add a progressbar message to ask the user to wait.

I use a BackgroundWorker to do the sql query on a static object.

the code workds fine outside of saleslogix, but when I add the DLL to saleslogix through .Net Extensions I get a Thread error.

I know Saleslogix is single thread, but is there a simple way around this?

How are you using the background worker. Are you trying to update a UI control and if so are you testing to see if Control.Invoke is required.