My site, the Alternative Film Guide, has two different urls: "www.altfg.com" and "www.alternativefilmguide.com." Currently, both are subdomains within another "umbrella" domain name/space.

Both subdomain directories point to the "www.altfg.com" directory. Even though the index page is the same for both urls, altfg has a 5 PageRank (and 184 backlinks) while alternativefilmguide has a 0 PageRank (and zero backlinks).

I was wondering if the fact that altfg has *two* urls pointing to its main page -- one with PageRank "5"; the other with PageRank "0" -- is the reason why every couple of months Google gets confused and drops the site from view.

Generally, the site is in or near the top ten for a number of keywords. For whatever reason, beginning today a Google search for "altfg" shows the site itself appearing after several pages that link to it. Even then, it's not listed under the "normal" "www.altfg.com" url, but under the more obscure (and rank-less) url "alternativefilmguide.com." (Strangely, Google shows it just like that, without the "www.") Last time this happened was in early February, and it took nearly 4 weeks for Google to finally list the site again under its altfg.com url -- and near the top of the SERPs.

The question is: Does Google think the site is cheating and thus it gets penalized every now and then because the robots think that every altfg.com page has a copy with the same information? Or is it a computer glitch that every now and then loses "www.altfg.com" (with its "5" page ranking) and finds instead "alternativefilmguide.com" (with its "zero" page ranking)? Anyone has a suggestion as to how this problem could be solved?

(Note: I've just created a .htaccess redirect so that both "www.alternativefilmguide.com" and alternativefilmguide.com will be redirected to "www.altfg.com". I didn't know about that option until today. Should that solve the problem with Google's listings?)

Any suggestion will be much appreciated.