If you use ATSC with Media Center, and have mapped minor channels to listings, you probably noticed that the listings from the .1 channel are duplicated across the other minor channels (if the callsigns are similar enough).  This results in a display like this in the guide:

This is more than a little inconvenient, since it also means that Media Center cannot schedule recordings accurately on the affected channels.

Coming in the next rollup QFE for Media Center (late Q1/early Q2), we have a fix for the problem.  Unfortunately, the fix required a code change and cannot be worked around with a registry tweak.

The way it should look is like this: