I've run into the same thing with some out of the way TGP banning or blacklisting a gallery that all the picky ones posted. Best way to handle it is like you said, I removed them from my submit list.
As to TGP's beginning to disappear, it was bound to happen. There was a huge wave of new TGP's in the last few years, every webmaster wanted their own, now they are finding out that they are hard work to do right and more time consuming than they thought so they are letting them go.
As someone who has owned and operated traffic pumps, including TGP's, for 8 years now, I just waited this new fad out. The up side for me is that a ton of dissatisfied TGP traffic finds it way to one of mine
