I don't think so that it is just because of google dance. When you stop link building, then your competitors keeps on doing link building and after one week, your competitor site was on top then your site.

im pretty sure thats a google dance.... it will dance a while before it settles..... more likely than not you will end up in a better position.... unless your in a crazy market of course as stated previously....

I think adding the forum links gave you a temporary boost and then things settled down. Not sure if you want to call that the google "dance" or not but one this is for sure and that is that the SERPS are not static so you will always see changes in your position.

One thing you might want to check is if your forum profile backlinks are still there and still dofollow. I know it's rather common for these types of profiles to get deleted once the owners of the forums realize you are just there to drop your link so it could just be that you don't have as many links as you did when you were at #7.

You could try getting some higher PR links like from blog commenting or something to give some diversity and a better boost, maybe?

Lee

Even I am having a similar problem.
I am currently having a site which is having PR4,but before it was having PR of 1,it was ranking in the 4th position for a specific keyword,after that I decided I will add some backlinks and boost its search engine position,but unfortunately my position dropped for that keyword and its no where to be seen for that search position inspite of the fact that the 2 keyword is present in the domain name of that domain name which I registered.But my PR rose to PR4.
Can somebody help me on what do I need to do for this?

no worries bro.. relax.... try this site:yourdomainname.com ... if you still see your site your fine... if not u have been deindexed (unlikely, unless you have been a bad boy)...

after your linkbuilding activity, the spider has responsibility to find them (the links to your site).... when they find them, google has a duty to recalculate things in regards to your site..... when google recalculates, it is normal to find your website gone for 1 day for up to a week or a little more.. when your site is finally back, you get to see whether or not your linkbuilding activity bears fruit

Thanks everyone,I will try more backlinking and report the results.

I heard that backlinking too much will cause your site to be banned or semi banned thus slapping from the search result.That is what I have experienced.