MediaLab freezes, running on Vista

[braseg]

We are building a study that includes a large number of variables (multiple personality instruments), and are having a problem with MediaLab freezing up after about 150 items. Specifically, after an arbitrary item it will go to a blank purple screen and nothing new will come up. We have found a few clues as to what is going on:

1. It does not happen on a computer we have that is still running MicroSoft XP. It only happens with Vista
2. The ctrl-alt-right arrow will exit the program if done immediately, but if one continues to press keys after reaching the blank purple screen it will lock up the program completely.

Any thoughts?
Thanks

[jarvis24]

How reliable is this? e.g., It happens every time, or x out of n sessions? When it does stop, what item type is it that it freezes on?

How arbitrary is the item--You mentioned it's after 150 items or so but what kind of variation is there here? Are we talking 149-151 sort of thing or a 140-160 kind of thing?

Also when it does freeze up after hitting a variety of keys, does it help if you click on the black border at the bottom and then pressing ctrl+alt+right (or just ctrl-right to got to the next item)?

[braseg]

So far, it has frozen every time we try to run the full experiment (running the individual questionnaires, all are fine).

Because the questionnaires are presented in random order, it stops on different items each time --usually a Scale Response item, because those are the most commonly used -- but it is consistently at about item 145-155. If it has to do with the number of items written into the data files, then it is about item 160-170 (i.e., including time stamps, instructions, "ok" statements, etc.).

Once frozen, neither ctrl+right or ctrl+alt+right works; the only escape we've found (so far) is ctrl+alt+delete to get the Task Manager.

[braseg]

Further information based on our efforts to figure out what is going on:
a) The program locks up after a certain number of responses have been made, regardless of how many experiments are run. I.e., somethings (Vista?) is tracking the total number of responses. We can run through a whole experiment that is lengthy but not long enough to reach the lock up point, then start another experiment and the second experiment will lock up quickly as it reaches the lock up point (based on the total responses across both experiments).
b) If we run an experiment, close MediaLab, and then run a second experiment, the total number of responses factor resets to zero.

[jarvis24]

This is really useful information. I agree it certainly sounds like some kind of memory issue--especially if closing and restarting MediaLab allows for the "count" to reset. My only remaining question is whether this also depends on some specific content in the experiment (i.e., a 3-way OS x #Items x Content interaction) or a simple 2-way OS x #Items interaction. Without seeing the content of your questionnaires I can't say. But one way to tell would be to administer a 200 item questionnaire, with the most basic content possible--say 200 instruction items. I've attached such a sample que file. Would you mind running it on your system and see if the result is the same?

[braseg]

The 200 item questionnaire freezes right after instruction item number 156 (every time, for three consecutive trials).