I installed apache about a month ago and im getting these weird requests for the file /default.ida. It goes kinda like this:

x.x.x.x [date] "GET /default.ida?XXX[LOTS_of_'x's]XXX%u9090%u6858%ucbd3%u7801%u and then that %u... repeats sometimes with different numbers, sometimes the same. It ends with a %u=a HTTP/1.0"

I see this from many different IPs. I telneted myself and did the same thing but nothing came back. I checked out one of the guys that did this (he had like a dozen ports open), loaded his webpage and it was some 31337 dud3 who hates the government. Is this some kind of exploit that doesnt work? One more question, i port scan myself, but i cant find the logs anywhere! Is the stealth mode really good, or am i looking in the wrong place? thanks guys
Ryan