Yes, I have also been using the same method to use our epson printers.
We installed Bounjor Print services for windows, and were able to configure our Ethernet connected Epson Printers and use them via windows as print server for our iPAD.
This stopped working from the ipad when version IOS 5.0 was installed.
You can find the procedure that used to work at this link
http://ipadhelp.com/ipad-help/how-to-enable-airprint-for-windows-and-use-any-pri nter/
They have also updated the file and have also identified the problem, but now the only option being made available to work is Collobos Software at an additional purchase fee....Versus free previously.
It should be noted that the Windows Bounjour software still identifies the epson printers, and they can be printedto via the spooler on a windows machine from a windows machine. I assume, that there is something in the Apple IOS 5 software that is not allowing for the use of the windows based services to NON HP printers...