Dup Content Penalty

Problem with review page disappearing from Google Index

[montydons]

I decided to write a piece for a well known review site and used about 75% of my main review page unedited including a link to my site. The review site removed my link from the text and since then my page has dropped out of the G index.

After reading posts on this board I realised that duplicate content is a problem in G. I rewrote the page but it is impossible to make it completely different. Today after 3 months the page is showing up
as a "Supplimentry Result". Does anyone know if this is the first step to recovery as I thought this only applied to old pages that are about to drop out the index? Also, does anyone know an approximate percentage difference I need between the pages to avoid the duplicate penalty.

And finally .. if I completely changed the content of my page how long would it take to be cached again?