Radical fluctuations in position...

Having been in the SEO game for a couple of years now; I'm used to fluctuations, where my site will be number 9 one day, the next it'll be 6th and two days later it'll be back to 9th and so until Google settles down.

What I've been seeing lately though is something different. I typed in "Dubai Cranes" this morning and saw my site (see signature) at number 5. An hour later or so a colleague typed in Dubai Cranes into Google and said the site was at number 7. Perplexed, I queried Google again with the term and the site was indeed at the 7th spot. I refreshed the page immediately, and saw my site now 6th in the results.

Anyone else seeing this kind of fluctuation? I'm not worried, the site is doing exceedingly well considering it's age (3 months old).

NB: Within 30 minutes of writing the above thread, the website is now in position 8.

Check if you are logged into a Google Account

Check the data center each time.

This isn't too unusual. I have seen data centers flicking in and out regularly. I think G does this when they are testing a new feature.
Some SERPs it makes a massive difference on and others it doesn't.

Its nothing to worry about.