Ruby interpreter dies with system popup message

I sometimes get this message on a dev box I log into remotely:

Ruby Interpreter (CUI) 1.9.2p180 [i386-mingw32] has stopped working

A problem caused the program to stop working correctly. Windows will
close the program and notify you if a solution is available.

I basically have a a couple of ruby daemons and a couple of Rails
servers. I recently had a problem with just one rails server and a
program that uploads pdfs to the rails server and no daemons running.
There is no error messages in the logs and the error seems to be
inconsistent. I can upload a couple of files ok, then the message
appears as a popup and it causes the rails server to die. What can I
try to troubleshoot this ? Any ideas ? It concerns me a great deal
that there is no real diagnostic message, stack dump etc …

The system appears to be:

Intel® Xeon® CPU E5310 @ 160Ghz (2 processors)
24.0 GB Ram
64 bit operating system

but I am not always the only person logged on, though the system does
not appear to have much of a load most of the time …

A note on my latest test with this problem is that if I run the
upload script that uploads pdf files to the rails server and try to
access a web page from a browser on the server while that script is
running, it seems to cause the problem. If I just run the script
without accessing the web page, it seems to be ok. It seems like it’s
related to system load in some way is my impression …

This whole system is eventually going to linux at some point, so
hopefully if that happens the diagnostics will be better then …