Hmm, good question. I haven’t encountered this before (and on my local install I can’t even locate any feed caches anywhere), but I’ll put it on the list ti look into.
On your 03/26/15 date, you have an extremely long link posted as text (rather than actually hyperlinked to a shorter piece of text). This is forcing the table to be as wide as needed to accommodate that unbroken strong of characters.
It looks like your GigPress settings got wiped somehow, whiched messed up the permissions for the plugin. I deactivated then reactivated GigPress and resaved the settings – all is working now.