I'm not familiar with the site (or software) - but, it appears to be a security cam service. Is it possible that the software is recording the video and filling up your hard drive?
Lack of sufficient free space will definitely lead to problems.
Another approach would be using something like MSN Messenger, which provides web cam support.
The article below describes how to use the product -
How to have a video conversation with MSN Messenger Try it and see if the issue persists.