My best guess on this so far may be the MWS's only having 256mb of RAM...in almost every case, the issue can't be reproduced on the store server, or on our own machines. In some cases, there are outside forces at work such as malware, or inappropriate software installations. Unfortunately, inventory functions as a java popup, using a very old version of java, and causes it's own problems. It also has windows interaction issues(Doesn't respond to graphics setting changes) There have been some HD replacements that have had some impact, as well as ram upgrades, and even full hardware upgrades, that have also made some improvement. One of my concerns is that the databases are getting very big, and a lot of the issues they report, have a lot to do with reporting and data entry.
Mike has more information on this.