Unable to see ext HDD when connected Mac to Mac

Hi guys,

I have just recently started sharing files over wireless and until the other day I had no problems. That problem being - when I log on I cannot see any external HDD's attached to the computer Im connecting with. I have an iMac and a MacbookPro - both on Snow Leopard.

Has this happened to any of you? Its probably an easy fix, I just cant think of any settings I've changed to make this an issue...

Any help would be appreciated!

Try clicking on Finder does it show up there if so click on it also this is assuming you have
file sharing checked in system preferences.