I've got a similar problem:
http://www.lawnsite.com
http://www.lawnsite.com/forumdisplay.php?f=123
That's one BB with an internal style set to one of the forums, so you get a "Lawnsite" style and "LHDB Site" style.
I've set up the search in the LHDB style to search only within that forum (and child forums). The problem is, when you search, it sets the style back to Lawnsite's style, but only shows results from LHDB Site (forum). What I wanted to do was set another $_POST variable (forumstyle) that would be picked up in the "style_fetch" hook, and set the style to LHDB site (so that people don't get confused, and so when they search again they'll again be searching LHDB... basically making them seem like two separate websites).
I then tried to use a cookie, but it seems to work intermittently...
I'd much rather go with the $_POST method, but I can't seem to get the variable back in the style_fetch hook... Is there some way I can get ahold of this variable without actually editing the search.php file?
--------------- Added [DATE]1267122981[/DATE] at [TIME]1267122981[/TIME] ---------------
Well, I went with a cookie that expires in 5 seconds... if anyone has a suggestion that's better than this, please let me know!!! I'm still curious as to how we can get ahold of $_POST data through hooks after a search... and still use this information to change the style with style_fetch.
vBulletin is such a massive beast... ><