The yeast not propogating, IMO, is the weird part. I had a lactobacillus infection that spread through to 2 batches (well, 3, if you count the one as a split batch) and although it was definitely apparent, it didn't show up until AFTER the primary was already over. It sounds to me like you may have had dead yeast, or the numbers are so low that it's still building up cell counts and hasn't started fermentation but the infection has.
If you've got an old smack pack, make a starter . I've been making them for all of my liquid yeast batches, maybe because I want an excuse to use my stirplate. In any case, making sure your yeast is viable prior to pitching saves you some headaches for sure
If you haven't already dumped it....ride it out! I drank the Oatmeal Stout that was infected through pretty quickly and it turned out great. The body was definitely too thin because of the infection but otherwise the off-flavors didn't have too much time to develop.
I've still got the batch in the carboy, I'm not dumping it yet. However, I'm debating whether or not to buy another smack pack and pitch it just to see what happens.