Why can't I get indexed?

[kenfuzed]

I'm getting really frustrated, and I'm starting to think there's something wrong with my forum. No matter what I do I can't seem to get listed with Google, while Yahoo has me listed with 1300 links. The forum is Bike-Talk.com

Late last year I acquired this forum from a shop that was going out of business. I migrated the forum to a new domain and host in November. I have since spent hundreds of hours rebuilding the whole forum to have a cleaner look, installed several mods/hacks to make it more user friendly (and SE friendly)... yet to this day I still do not have a single page listed with Google.

I'm running the SEO sitemap generator creating both the Google and Yahoo sitemaps daily. In my sitemap account over at Google there are no errors and the map is being crawled. A few weeks back I installed vBSEO to see if that would help any. Still nothing!

What makes this more frustrating, as an experiment I built a quickie wordpress blog and only posted twice. Submitted a sitemap using the same Google account, and a week later its already listed!

There are usually around 40 to 50 users online during the day. While the membership is over 2400 there are probably only a few hundred that frequent the site on a regular basis. My stats run about like this:

Threads: 3,099, This Month: 96 (112%)
Posts: 18,997, This Month: 688 (103%)
Members: 2,425, This Month: 36 (5%)

Mods and hacks installed to improve the forum include:
vBadvanced
vbseo sitemap generator
Welcome Headers
Limited Guest Viewing
Email Inactive user mod
vBSEO
Photoplog (+ enhnacements)
EZ Archive plugin
Automatic Welcome Thread

Plus several template edits

How can I find out if I've been blackballed from Google? My older website (Harley Performance) and that stupid gag blog are ok with Google, its just my forum that is tanking.