Tags Keep Or Remove? SEO Help

About a little less than a year ago, my site was bumping, had great google results etc. Lately, everything is gone, no traffic, 1 google search result, etc. I installed SEO back in May and still awaiting some results, but in the meantime, what's the deal with tags? I have them on now, but I feel they may be hurting or not helping at least.

In regards to SEO, should I turn off tags on my forums and remove them all from my threads? I think by default they are submitted in your sitemap right? So that means mine are, with the sitemap generator, however I have this in my robots.txt file for some reason:
Disallow: /forums/tags.php

Anyways, any insight?

I keep tags in place however only site staffis allowed to add tags to pages. But i don't add them to my sitemap files.

As long as you are using vbseo, tags.php will never be a page. it will be tags/ (or whatever your ruleset dictates). So, blocking tags.php really isn't doing anything.

I have tags on and available for bots to see, but i do not include them in my sitemap.