Used digg on an article. Got indexed and then deindexed

It's exactly as I've written in the title! I posted an article yesterday on my website and digged it! Google hasn't been visiting my website for a while now and I thought it will do good if I sent him a good ping (literally, he hasn't been visiting my website since sept. 2011!!!, robots.txt is ok, I assure you)! I did send him a ping and the article was in google in no time! I didn't hope for any good SERPs but I at least wanted indexation (is it too much? lool).
Now after I've checked again, I saw that the page got dexindexed! The article is still on digg, it has not been removed, flagged, banned etc but mr. G decided to deindex the page!
Moreover, I've noticed today that I have an older site with a ton of original articles that did not get indexed! I really need some help here!
I hope you could help me a bit! Thanks!

strange. never heard of such before.

Hi

Just keep building backlinks from social sites and blog comments for a few days and then see the results after a week or two. Use your anchor text in a randon way not your main keyword. Use multiple variations of the keyword.

This happens sometimes because google needs to sync changes over all its servers worldwide. Give it a day or 2, you will come back. Digging an article once shouldn't really get your article deindexed. lol