is this for the TM-T88III / IV printers ? or another model?
I work with the 88III / 88IV all the time.
when I set codes I am using the seperate codes and that works -- the one you are using is a short-hand to toggle several things at one time.
I am still using the ole /COM bits but have been planning to switch.
was it you and I that posted some about this before ?? can't recall it was at least 1-2 months back.
if you want to keep using the zero there may be a way to make it work but it may be that you have to skip string builder or you may have to get it to use ASCII encoding or some other tricks.
I bet by default the internal buffers used by SB use a char 0 terminator to find the end of the valid text. normaly text strings do not contain values below 32 / space and by default .Net works in UNICODE which is not bytes
but the Epson Codes are Bytes not chars if you get what I mean ?