Yes, I've been seeing this happen too. I started when I changed something with the registration process because the old way was generating errors and preventing people from registering at all. I'll have to explore how to fix the problem for good, but right now I'm backlogged in other projects, especially with Platform Builder and the graphics update still on its way.
Until then, just keep reporting spam posts and I'll try my best to stay on top of it.
Thanks for hanging in there.