Strange Position Jumping Last Few Months

[vetofunk]

I have a client that has had some really strange positioning changes over the past couple months. This actually started in the summer...

The biggest term for their site dropped to page 10+ over night...plural and singular. They had previously held position 1 for about 3 years. Fearing a penalty for possible over optimization, I went through and reversed a lot of my link text and toned down the on-site optimization. About 2 months later they jumped back to number 1 for both terms.

This position lasted about one month and then the main plural term jumped down to #12. The singular jumped to page 2. This was about 2 months ago. Then about 2 weeks ago their second most popular term jumped down to #7, where it had held number 1 for about 4 years.

Then last Friday night all terms jumped back to #1 and are still their this morning.

Do you think I am on the brink of some sort of penalty? These are some strange jumps going on.

[tedster]

This is just a guess, of course, but it might be some kind of weakness in your backlink profile.

I'm guessing here that different searches at different times are accessing different data centers, and some of those data sets have your site at depressed rankings. I'd suggest you start monitoring which Google IP is replying to your queries - you can use the ShowIP add-on for Firefox to do that most accurately. That will soon show you if my guess is right.