Epson purposely designed the firmware of those printers (for the north American markets only) to lock up when it detects non OEM ink cartridges. Additionally, the OEM carts are not designed to be refilled or reset. I spoke to Jon Cone (inkjetmall.com) about this and he estimates that these...
I just came across this post so I'll apologize in advance if the issue has been resolved. When I had my 4800's, I used both cone color and piezography in both and utilized pezioflush. Flush was designed to dissolve ink but does need time and is recommended to allow it to so so for 24 to 48...
Just found out about this forum via a post on the Luminous Landscape website.
I've been into photography since '72 when I was in college and became interested in the darkroom side shortly thereafter. Did my own film & printing in a makeshift darkroom in my parents basement, then in my apartment...