SuperLab- not responding

I have an experiment where there are nearly 1000 events in the form of image files.When I am trying to run the experiment, it goes into a eternal freeze.Nothing seems to move.Then, sometimes, if I try to escape, the program starts magically.I have tried to divide the experiment into blocks of 250 and the problem still basically exists.
The following is the specification of my computer
In my C drive, I have nearly 1.5 GB free
Its a 1.6GHz machine with 512 MB of RAM.
OS is Windows XP.
Its kind of urgent.Any input would be greatly appreciated.

This is just a shot in the dark without seeing your experiment, but it sounds like you might be loading all of your stimuli before the experiment runs. I’m guessing this is causing problems because you only have 512MB of RAM and 1.5GB free on your boot drive. In the experiment options window, tell SuperLab to only load the stimuli on a per-trial basis. See if this makes a difference. If so, you may want to get more RAM or free up hard drive space (RAM would be preferable, but you probably need to free up hard drive space anyway).

If this doesn’t make a difference, let me know.

Did all, added RAM, freed HDD and made the per trial thing.Thanks.
It works now,partly.
Except that in some trials, the registering the response is not happening in 1 key press…may be 2, sometimes 3, and that too in a subset of trials, say 5% or less.What could be happening?

Anything that I suggest as to why a response sometimes requires 2 or 3 key presses would be nothing but a guess without seeing the experiment. If you like, we can setup a phone appointment and I can login into your computer to take a look at the experiment. Let me know.