Scheduled Recordings Disappearing?

We've had a problem with shows we've setup to record just NOT recording or a series setup tpo record only getting one or two episodes then stop recording any at all even though we've told it to hold 5, 10 or even ALL the recordings until we delete them.

I ALWAYS setup Monday Night Football and two specific teams to record EVERY week during the NFL season, plus a few more I might be interested in.

This week alone, I've had two different games just NOT record and not even show up as being skipped, cancelled or deleted in the Recordings Manager.

Anyone else have this problem lately?

To answer a few questions before they're asked:

Our DVR has 67% free space, the main box itself was just replaced a month or more ago and the problem has recurred with the replacement box. It also does not seem to matter if its a new series/one time show we're setting up to record or one we've had setup for a long time or what number the series is listed as in the recording manager's 1-99 lineup.