In August of 2006, I had Advent Product Development do a patent search
For an idea I had. They recommended that I go forward and have them patent and develop the idea. At that time I did'nt have the money.

In Feduary 2010, I had the money to go forward. I contacted another company called Invention Home. They did a patent search, and found an invention just like mines. It was patented in 1994. In the patent discription, it said every word I said, just like I said it in my discription. I
Feel that my idea was stold, and back dated.

My question, is it possible, and if so, how can I prove it.

Check with the US Patent Office, they don't let back dating happen and would be interested in investigating this claim. It was a US Patent, right?

No - it's not possible to back date a patent. If the patent was granted in 1994, then it was probably originally filed with the Patent and Trademark Office (PTO) in 1993 or perhaps even earlier. If you want to pursue this, you can have your patent attorney order up the "wrapper" files from the PTO, which contains the correspondence between the patent examiner and the inventor - this can be an interesting way to see the specifics of how the PTO went through their analysis of the patent.

By the way, if it were possible to steal an idea and back date a patent they certainly would not have picked 1994 as the date of issue - given that a patent granted in 1994 has only one or two more years before it expires (patents are good for 17 years from date of issue, or 20 years from date of filing, whichever is later). It would have been smarter to pick a date a year or two before your initial discussions with Advent Product Develoipment.