(I've never visited Disneyland Resort, Tokyo Disney Resort, Disneyland Resort Paris, nor Hong Kong Disneyland Resort, so don't be fooled when I pretend to know what I'm talking about. [But I'm pretty good with the information, if I do say so myself. And you can hit me all you want with Walt Disney World.])
Ahhh...it has to do with the system. Ok. I knew there was a catch to it. :P
I only ask because the searches count for the 'New Posts' tab which I happen to be very trigger happy with that button.
As others have mentioned... usercp doesn't do a search the same and therefore doesn't have the throttling. You can view all the threads you are subscribed to right from the CP. It's the quickest way to get to your activity.. and then when done check out 'new posts' for threads you haven't been active in. It's a good way to surf the site. Good luck!