It appears this is related to new channels recently appearing? For example, I see four new channels (4.4, 4.5, 4.6, 4.7) were added by one station. On the Schedules Direct listing, I do not see these new channels appearing. So, maybe that is why the red bars appear?
These four channels also appear with red bars in EPG123 client. (NOTE: I had to reinstall the drivers for my tuners which resulted in having to redo the setup of WMC which resulted in the loss of all my channel info I had manually entered.

On the current version 1.6.0