Opening files in Word/Excel

Bit of an annoying one this.

With 2 of our Windows 2000 clients using the Open dialogue box in Word and Excel when the click the drop down arrow to select a network drive it takes up to 20 seconds for the drop down list with all the drives in to appear. Tries searching the MS KB to no avail so far.

Anyone had this and anaged to cure??

Regards,

Paul