Hey Jack that's weird! What tool were you using? (actually i don't think it's tool related)... Try and toss your "pref" file and see if it snaps back.

To clear your PREF file, locate it (should be somewhere like...) C:Documents and SettingsusernameApplication DataAdobePhotoshop7.0Adobe Photoshop 7.0 Settings (file name=Adobe Photoshop 7.0 Prefs.psp) - rename it Adobe Photoshop 7.0 PrefsOLD.psp (or just delete if you feel "daring")

or if you want to do it by "keystroke", quit PS and re-launch it and hold down Command-Option-Shift. Youll be asked if you want to delete the Preferences.

Click OK and see if it comes back...

:)
scott