Question : Access 2007 Slow on Subforms

I have a database 315K that is extremely slow when using a drop-down box on a subform.  When clicking the drop-down you can literally see the records display at a rate of about 2 seconds per line.  The drop-down is bound to a query.  I have tried the following things to speed it up to no avail, so thought I would post to see what others might suggest: (This behavior does not exist when I'm running on an external drive, but when loading it on a network it crawls.)

1. Compact and Repaired the database (we do this on a regular basis)
2. Turned of Name Autocorrect
3. Turned of subdata sheets
4. Compiled the VBA code
5. Tried loading the row source for the combo box when loading the form

Any suggestions will be helpful.  It's painful to watch the users have to wait so long to select from a combo box.

Answer : Access 2007 Slow on Subforms

Is the query in the row source slow to run when running on the network? What kind of network?