About 1 month ago my backlink from a PR6 was removed. My website had a PR5 with a bunch of PR4 and one PR6 before the update. I now lost that PR6 Backlink about a month ago and now my PR5 dropped to a PR3 during this update and i was buried in the index. i used to enjoy a # 9 spot on a very popular keyword and now during the update it bumped me to # 225 on that same keyword. can that happen? by losing a PR6 backlink can i get bumped from #9 to #225 on a keyword search?