Every so often when I am using a MMC that I created, the tab and backspace key quit working. They still work in other programs, but give no response in the MMC.

I am running Windows 7 Pro 64b. The MMC has DNS, Event viewers [for DCs], AD users and computers, and GPMC in it. It is primarily when I am using the AD portion that I notice the trouble.

Anyone else run into this?