A reconsideration request dilemma

I just can't find the possible violations :(

[nervo]

One of my sites completely vanished from the serps some time ago. The site is 1.5 years old and previously reached PR3 but then after the last update it dropped to zero. Using operator "site:" Google shows zero pages. I also noticed in my G webmaster tools that the last time gbot visited the site was back in January, although I kept resubmitting the fresh site map.

Now, it's obvious that something is very wrong with the site, but I couldn't determine the cause(s). So I thought of submitting a reconsideration request but I'm hesitant because there it says to submit the request ONLY if issues have been corrected.

So, should I submit a reconsideration request although I haven't made any changes because I couldn't find the violations?
What would be the best way to act in this situation?
Thanks for help!

[bwnbwn]

Have you made sure the site hasn't been hacked. If you don't know the cause there has to be something that got you banned.

[nervo]

To be honest, I have no idea about how to defend from the hackers...

[bwnbwn]

How is your site hosted on a shared server, dedicated, at home?

[MarkWolk]

Make sure that no other site has copied excerpts of yours. I got hit by duplicate content penalty because 2 other sites have copied lots of content from mine. It is not supposed to harm your site; but when Google malfunctions, it does.

Search for duplicates using Copyscape, or simply copy phrases of ca 10 words that are specific to your site, and paste the in the Google search box between quotes. You should get results only from your own site. If other sites appear in the search results, visit them and assess whether they have copied your content. All that work must be done page-by-page.

[nervo]

It's on a shared server..

[Bewenched]

I had relatively the same thing happen over a year ago, ...not the entire site, but a large chunk of it. Sadly we hadnt done anything, but were hit with duplicate content due to several sites doing the 301 hijack technique, which I still battle all the time. Google claims to have that fixed, but it's really not... just patched.

To combat this I set up google alerts to notify me of certain terms specific to only my site and when it find it, it emails me, then I go to google sitemaps and report the spammy site. Seems to be helping, but we are still down from what we were two years ago.

[nervo]

I already use google alerts but so far I haven't noticed any major issues with the copied content...
BTW how can I detect possible 301 hijack?

Do you guys think it's safe to ask google for help or something?