Jing seems to have potential to do just what i want, but i am running in another problem: when i run jing to record, whatever program i am using becomes sluggish, and the cursor just blinks too slowly which makes it nearly impossible to use. Someone suggested i get more RAMs as i have "only" 1.5Gb but that is likely not the problem since the program works fine on my work computer, which has only 512Mb RAM. So, what else should i look at? What else could be the culprit?

PS. using the trial version of Camtasia gives me the exact same problem.