Internet Explorer - Press Return to do search - does not execute

Using Drupal 6.0 Beta 4

If you do a search using firefox, latest, enter the search term and press the return key rather than the search button - search executes correctly.

If you do a search using Internet Explorer (ver 7.0.5730.11) , enter the search term and press the return key rather than the search button - search does not execute - screen flickers but no search processed.

On both browsers, if you enter the search term, and do the search using the "search" button - search works OK

Hope this is of some use

Alex