Microsoft has suspended the beta testing of the next version of its MSN Messenger client because of a potential security problem, a company spokesperson says.

Testers discovered a potential security issue in the early version of MSN Messenger 7.0 shortly after Microsoft made the instant messaging client available to a select group of testers over the weekend, according to postings on MSN Messenger enthusiast website Mess.be.

The problem lies in a new MSN Messenger feature dubbed "winks" that allows users to send each other sound animations. The feature can be abused to overwhelm a user's system, according to the website.

The company has decided put the test on hold and pull the software while it looks into the issue. It will make available a new version of the client, one without the winks feature, probably some time next week, the spokesperson says.