Google doesn't necessarily have certain variables such as ?id= blocked. What it is is that Google doesn't want to index URLs containing a session ID (that long value like 8482349809934 ...) ... if you don't know what I'm talking about, check out any page on Amazon.com

In any case, Google doesn't block variables such as ?id= or ?sid= but rather any variable that has a value that resembles a session ID.

Regardless, I found out my problem. I was doing a google serch for site:www.daniweb.com daniweb to return all URLs in the daniweb.com domain that contain the word "daniweb" - basically to estimate how many of my pages are indexed with Google. Apparently my member profile pages just had the word "daniweb" more prominently than my other pages, which wouldn't display until I clicked on the "show all pages" link at the end of the Google search results.

Regardless, guests have now been prohibited from viewing member pages, so Google won't see this anymore anyways site:www.daniweb.com daniweb