Did not lube the seal, but it is cracked in one place (right where the leak is). I had thought about trying to seal the crack with some weatherstrip adhesive, but even if that works (I have no idea if it would), I'd only be buying time, as I'm sure the gasket will fail in other spots soon enough.

Thanks everyone else for the suggestions. I will bite the bullet and buy the OE seal, even though it seems overpriced (just bought an expensive OE sunroof seal, too). Besides lasting longer, from what I've read, the OE seals fit better and are just easier to install.