PR Storm and Getting Deindexed

I created a blog for the first time trying to sell my ebook and I'm trying to rank on a very highly competitive and highly searched keyword. When I finally got indexed by google, I was nowhere to be found on the main keyword (I was on the first page for my other targeted keywords but they are not as highly searched as my main one). After using PRStorm and an auto-directory submitter, I got to the 10th page Ya I know I won't get any traffic but it's a start. This was about 4 days ago. I checked again today and now I'm on the 7th page Seems like its working.

Now my question: Is it possible to get deindexed by Google for spam while using PRStorm. If thats the case should I stop using it and try some other methods to rank higher? Because I don't want all my hard work to disappear.

Anybody have any experience with getting deindexed for spamming backlinks?

Thanks

what i have noticed about every search engine is that if you stop building backlinks, they will notice and get you back on 2, 3, 4th page and way back...

so just keep doing what you are doing