Google penalty effect and recovery

I thought id share a problem im currently experiencing, and recovering from, and would like this to be a warning to other affiliates and hopefully to gain some insight from others who may have been penalised by google.

Around 4 weeks ago i noticed a few keyword search terms that i ranked highly for on my mainsite where no where to be seen in google, after spending a few hours grabbing blocks of text from all sections of my site and searching them in google, without quotes “” (this is a basc test to see if google has penalised your pages, if they rank below sites with less relevance, then you are likely penalised) i found 3 sections had been penalised, i say sections as the site in question is wordpress and the sections are categories, which i use to structure my site, so every post within the penalised category will not rank, so infact i had over 40 pages which no longer ranked, and these where important pages which got the bulk of my traffic.
The reason for the penalty
Im still not 100% sure on this but i believe the reason was the way i redirected mobile and tablet(ipad) users to a custom mobile squeze page. This in my thinking should have been no problem as i was just offering mobile users a simpler to use version of my site..BUT this is not the way google sees it. It took me a week before seeing it in the folowng light, if a mobile user searchs for a term such as ‘supercasino.com no deposit code’ and finds my site result in google for this article, clicks, he isnt taken to the article/post about supercasino, he gets redirected to my mobile page with no info on what he wanted, this mobile page is also set to ‘noindex, nofollow” as i dont want it to rank on its own. This im sure is enough to activate the filters and mark these high ranking sections/posts as cloaking/redirecting pages.
Recovering
The first thing to do was to drop this redirect code and the page in question i was redirecting to and to simply offer a mobile theme for the site. This next part was a little silly of me but in a rush to get my pages ranking again, i changed the url structure of 2 of the categories so google would reindex them and by not 301 redirecting the old urls, the penalty would also not be carried over, this works but ofcourse you lose all the links that help the categories rank well. in the last few days the 1 section that i did not change or do anything to has by the looks of it had the penalty dropped and has jumped right back up to where it previouly ranked along with all the posts that are within this section. This is great ofcourse but the question is now, do i 301 redirect the other 2 section urls to the new ones, maybe google has only lifted the penantly on this one section, im in 2 minds and dont want to further anger the google machine.
Warning to other affiliates
I have noticed a few other sites are using the custom mobile landing pages offered by fortune affilates and wagershare, which are great if used correctly, but if you are redirecting every page on your site to one custom ‘noindex, nofollw’ page, you are asking for trouble, it took google 3 months to penalise me.
Id like to hear from others who have suffered a penalty, or others that are uisng these mobile redirect pages with good effect, basically what is the correct way to redirect mobile users