Hi Peter, can you please explain what you mean by "0 for the margins". You see, the 3800 can't print 0-margin 17x25. in other words, you can't do borderless 17x25 on the 3800. There needs to be at least a 0.12" margin on each edge of the sheet. Maybe you meant something else?
Out of curiosity, have you tried printing a 17x25 from photoshop? I know you want to print from Lightroom; just trying to determine whether it's a LR setup issue or an Epson driver setup issue, or something else ...