Am i being sandboxed?

I officially launched my website on(18/03/06 with vbseo installed) a forum for a lot of car models currently available on the market. As u would expect a lot of my keywords are competitive i.e bmw or alfa romeo forums. I am already on the first page of yahoo for some of the models believe it or not. About two weeks ago one of them made it up to the second page of google for about two days and promtly vanished. During this brief period my traffic went up although not a lot but significant for a site just a couple of weeks old. Now not a single one of my keywords show up on google not even in the first 400 results or 40 pages. How long am I going to stay in the sandbox as it is called. I will like a direct reply from someone here who has experienced the same thing. I've encouraged some of my friends to register and currently have 454 pages on yahoo.
I cant help but imagine what the traffic will be like if google has mercy and releases all my keywords. some questions.
1) What was the increase in traffic like when your site was released.
2)Does google release the entire site or just some non competitive keywords.

If you didn't practice any black hat techniques you should be ok. Keywords should be no more than 2.5 to 3% per page for every word. More could make Google see it as keyword stuffing/ spamming. Check your keyword density here: Keyword Density Analyzer

Have you checked your indexed pages? This query on google and replace with your domain:

site:www.yourdomain.com

That shows all pages indexed.

I've just checked and with the exception of the word forum the rest are all under 2.5% then I dont think forum is a keyword. Like I said some of them are already no 1 on yahoo without problems. I am quite positive it is the sandbox and I've checked extensively with seo blogsites. And my site is only 7 weeks old. and about six weeks since it was cached by google so I guess I just have to be patient but I will keep u guys updated.

google has been off and on for the past 4 weeks or so. Everyone is changing results almost daily. There's a thread on hear called "big daddy update" or something like that that discusses this.

I'd say just hang out and wait for google to settle in like the rest of us There's not too much you can do.

I had my entire Blog Network (72 sites!) removed from Google for a few weeks.

We had e-mailed Google and asked what was wrong, and they responded with a TOS violation. We had all of our blog network sites inter-linked to each other; Google apparently thought that we were trying to set up a link farm to increase our PR for our main site.

Google does like to play with sites to see how they respond. When we were hitting the top few results for "Sports Blog Network," our AdSense revenue skyrocketed. When we were taken out of the listings, our AdSense revenue obviously dropped.

Needless to say, it scared the holy heck out of us... but thankfully, we're back in the results!

Wow - 72 sites. That's quite a network - sounds like you're doing well!

Originally Posted by Joe Ward

Wow - 72 sites. That's quite a network - sounds like you're doing well!

Trying to, anyway!

Our forum used to be the main source of revenue with the AdSense program. We changed the URL from /forum to /lounge to facilitate the Invision Power Board to vB switch and lost all of our Google 'juice.'

We're running two dedicated servers -- one for the blog network and one for the forum.