I have been tracking a Google AdWords bug via a WebmasterWorld thread for several days now. The bug is that AdWords professionals who have linked client accounts within the My Client Center (MCC) are unlinking - so AdWords managers cannot access those accounts easily.
The bug was first reported on June 16th. AdWordsAdvisor confirmed the bug on June 18th. Yesterday, June 25th, the bug seemed to have gotten worse, by spreading to many more AdWords advertisers and professionals.
In addition to the unlinking of client accounts, some AdWords professionals are noticing this message:
Your qualification is at risk.
You are at risk of losing your qualification due to low account spending. To retain your qualification, you must maintain the minimum account spending level.
Forum discussion at WebmasterWorld.