So a dynamic tracking url was created to redirect and measure traffic from ppc ads on an external site. This dynamic URL leads to a page identical to a main page on my site, but it's not the same url, only the root of the url is the same. This new dynamic page was supposed to be set up so that it can't be crawled or indexed, but yesterday Google saved a cached copy of the page using the dynamic url (but they cut the identifying parameter off the very end of the URL) and penalized the main page on my site by removing all of the PR and not showing any external backlinks (there are many)

Has this happened to anyone else? Suggestions on what to do next?

My plan is to remove the dynamic url altogether both from our site and the redirecting site, upload some new optimized changes to the main page that lost PR (I was planning to update it anyway), and wait for it to get indexed again.

My site is developed in asp, which I don't know enough about at this point, but for some reason it seems we got penalized for having duplicate pages.

Any feedback would be appreciated.