First off - hats off to the devolpers of the awesome mIRC script known as Invision. Definitely the best out there IMHO.
My FServe has two triggers, one for large ISO's, and one for a few thousand roms that are mostly between 128k and 2mb. I have set my InstaSend limit to 2mb, because I don't think people should have to wait for such a small file. My problem is, is that I returned home and a bot had been requesting files, and there were ~20 sends underway, all to the same person. Additionally, my normal limit of 20 queues had been ignored and Invision had lined up 200 queues for the bot (it seemed to max out @ 200). Because of the ~20 sends at once, all of the sends failed for my min CPS limit, and my computer had become completely unresponsive and I had reset it actually thinking it was frozen.
If there is some more options about these limits that I have missed, sorry for bugging ya.