if you have the hopper scrolling with rpc requests... are you using cgminer? cgminer above 1.61 has been causing thisw.
I also had this problem about a week ago when I tried it out, it would run fine for a couple of hours, then it would start flooding the screen with mumbo-jumbo and stop doing useful work. Does the problem still persist with cgminer 2.0? Any chance of this getting fixed?