Hi
I had the same problems with my Epson printer and had to set up a different router just for that to connect but I've now found how to get it to work with gargoyle thanks to a post in german on the dd-wrt forum
Firstly, (and while your printer is still connected to your existing network) make sure you have EpsonNet Config installed and run it (download it from the Epson website if you don't have it). Connect to your printer using EpsonNet Config and go to the wireless config section. Type in your ssid and password (as it will be under gargoyle) and then change the encryption from AES (set as default in Epson and it wont work with AES) and change it to TKIP. Then send the changes to the printer, at this stage your printer may disconnect.
Now set up gargoyle and in gargoyle make sure you have tkip encryption enabled on your router. To do this use WinSCP to conenct to the router and In the wireless config file , if you currently see
option encryption 'psk2'
change it to
option encryption 'psk2+tkip+aes'
and save the file.
Then in a terminal session turn wifi off and back on with
wifi down
followed by
wifi up
(or reboot the router)
Once the wifi is back up your Epson should connect to the router! This has frustrated me for many many months and now it works
