Folder suddenly omitted from time machine backup, not listed in backupd

I'm running a webserver off of a 10.8.3 server Mac mini. Using an external HD for time machine backups.

Everything is working fine, apart from the most edited folder - called pics (used for an image dump for the website) which has stopped showing backup updates since november 2013. Anything before is still available in the usual weekly backup that time machine keeps.

Everything else backs up fine. Has a daily, weekly and monthly backup. Except for the one folder I would like to have a daily focus on.

I haven't lost any data yet, it's not my only backup. But now I'm wondering if this is the only folder with this problem.

I have done the com_apple_backup_excludeItem check and the folder doesn't show up there.

Is there a way I can fix this without restarting a bundle and is there a way I can prioritise certain folders?