If you print, say, some Espon-ish dotmatrix text with a few embedded `Condensed Enable/Disable' commands the MIME type of your file goes from ASCII-with-Escapes or PCL to `data' and CUPS throws it in the bin instead of printing it. By uncommenting two lines in the /etc/cups/mime.* and restarting CUPS, you get _really_ raw output.
It would be nice if there were some on-the-spot notice of this misbehaviour somewhere; CUPS (any recent version shipped with Cooker or 9.0) itself doesn't sem to have any. I can see why it is done (stops gonzos from printing program files, for example) but it was a bit of a bastard to debug, hardly mentioned on the Web anywhere. Perhaps Mandrake could push a suggestion up to the maintainer that they also offer (at the user-sees-on-menu level) a `bleeding' mode which is `really, really' raw. Cheers; Leon
