Another thing people can try is uninstalling the driver for the "Microsoft eHome Infrared Transceiver" that, I believe, gets installed with versions of Windows that include Media Center. I nuked this when I was having trouble getting certain characters in chat and I haven't had the client go poof since.
- Open Device Manager
- Click on "Keyboards" to open the tree.
- Right-Click on "Microsoft eHome MCIR 109 Keyboard" and choose "Uninstall", then click "Ok".
- Right-Click on "Microsoft eHome MCIR Keyboard" and choose "Uninstall", then click "Ok".
- Right-Click on "Microsoft eHome Remote Control Keyboard keys" and choose "Uninstall", then click "Ok".
- Click on "Human Interface Devices" to open the tree.
- Right-Click on "Microsoft eHome Infrared Transceiver" and choose "Disable", then click "Ok".
(Instructions lifted from
this thread)