The currency rates quoted on the page can come from a variety of sources, e.g. Yahoo Finance, IMF etc, depending on what is the most accessible that day. They're merely a guide to the current state of the currency market and not a definitive exchange rate. Although saying that, I think it was showing 2.67YTL a couple of days ago so 2.65YTL isn't that far out.
I'm working on an updated Snitz modification that gets the rates from the Turkish Central Bank but having a few problems with the license for the data feed. Personally I don't think their figures will be much different to those from Yahoo etc, but it will be a live rate - as opposed to the delayed rate (by about 20mins I think) it is just now.
JF