I just ran into a problem yesterday with overlapping shows being scheduled for today, last Monday and the prior Monday. Next week has most all the shows only on Monday with the rest of the week blank.
Attached is a screen shot of this week and next week.
Airtime: 2.4.1
OS: Ubuntu 12.04 LTS
PHP 5.3.10-1ubuntu3.8 with Suhosin-Patch (cli)
All the repeating shows were originally scheduled many weeks or months ago under version 2.3.x or 2.4. I don't think any shows have been scheduled under version 2.4.1 as that upgrade was performed about two weeks ago.
Yesterday it happened that Daylight Saving time ended here in the U.S on Sunday which may explain the blank slot in the schedule early on Sunday. But otherwise, don't know that it's related to this issue or not.