If you are using a custom theme that uses moviesheets, then you need to skip the 3.08.14 FW update or rollback to 3.07.14.
This is because TV Shows will no longer use custom moviesheets in this version. The xml code is no longer used and instead all of the backdrops are pulled from a single folder for the episodes with in a single folder (I have not tested any other way). And it also appears that you HAVE to use the internal scrapper to get even those backdrops to display.
EDIT: Just to be clear. No matter what has been said in the rest of this post, there is NO fix for this issue. There is a trick, but that involves renaming your files so that the HUB/SMP no longer recognizes the file as a TV Show. I do NOT recommend this as this is a BUG and will most likely be corrected in future firmware releases (fingers crossed).
The only true fix for this issue is to rollback the firmware to the prior release (3.07.14) and unless the current release fixes some issue that you had, rolling back should not effect your functionality.