Find Contacts -Advanced Search Displaying Incorrect Totals and paging

Version 4.0.6 Using Find Contacts -Advanced Search Using a custom field tick box and the change log modified between 06/01/11 leaving the second field blank. 73 contacts are returned. The screen says 198 contacts over four pages. Clicking from the 2nd to the third page the screen is thrown back to the search criteria with a no matches found message. The criteria appear filled in as they were. You press the search button again and the no matches found message comes up again. Leave the search completely and come back in and the process can be repeated. Despite it saying 198 contacts if an export is done from the first page, 73 contacts are exported.