[mike221]

I have the same problem :
Hosts : 38 Entries
Pages : 46105 Entries
Index : 11891757 Entries
Keywords : 307700 Entries
Temporary table : 495238 Entries

It runs Ok on 1.6.3 it is tooooooo slooooow on 1.8.0, specially with the exact words option.

Some times I get this message:
Fatal error: Maximum execution time of 30 seconds exceeded in /home/site/public_html/libs/search_function.php on line 305

Line 305 is :
$extract_content = preg_replace("/([ ]{2}|\n|\r|\r\n)/"," ",fread($f_handler,filesize($content_file)));