Bicycle Mechanics - small pulley thing

i have a lx rear derailleur on my trek 520 and i am getting high pitch sounds from certain rear ratios, i looked at the rear derailleur and noticed that the pulleys don't really look secure on it. i don't want to do something bad to the derailleur, but can i just tighten them? is there a certain amount of torque that you must aply to those pullies?
thanks

The top pulley is designed to slide side to side. this will not go away by tightening the bolt.

Be sure you don't over tighten them and bind up the bearings.

Also if the high pitch sound is continuous and seems to be like that mostly at higher speeds, continuous steady operation, then it is possible the problem is the bearings are running dry in the pulleys, not the tightness of the bolts.

I'd suggest taking them out and inspecting them, re-lube them and place them back in and tighten with proper torque (do not extremely tighten them).

I like good sealed bearing pulleys. The reduced friction may be negligible, but they save you the annoying job of removing, disassembling, cleaning, lubing, reassembling & remounting conventional pulleys.