Zebra->/dev/lp0->Cups->http broken

[eman resu]

A Zebra 2844 using the EPL2 1.3 drivers in Cups 1.3.4 (via gentoo portage) works fine locally via parallel port (thank you very much for that).
But when connecting from a windows machine via http, cups will report success without actually printing anything.

I'm certainly no cups veteran, but I took care in doing some research, but came up with nothing that yielded any clues.

Cups error_log (with debug turned on, and timestamps stipped):

cupsdReadClient: 8 POST /printers/barcode HTTP/1.1
cupsdAuthorize: No authentication data provided.
Get-Printer-Attributes http://192.168.2.158:631/printers/barcode
cupsdProcessIPPRequest: 8 status_code=0 (successful-ok)
cupsdReadClient: 14 POST /printers/barcode HTTP/1.1
cupsdAuthorize: No authentication data provided.
Get-Printer-Attributes http://192.168.2.158:631/printers/barcode
cupsdProcessIPPRequest: 14 status_code=0 (successful-ok)
cupsdReadClient: 8 POST /printers/barcode HTTP/1.1
cupsdAuthorize: No authentication data provided.
Print-Job http://192.168.2.158:631/printers/barcode
print_job: auto-typing file...
add_job: requesting-user-name="Rick"
Adding default job-sheets values "none,none"...
[Job 19] Adding start banner page "none".
Discarding unused job-created event...
[Job 19] Adding job file of type application/octet-stream.
[Job 19] Adding end banner page "none".
[Job 19] Queued on "barcode" by "Rick".
[Job 19] hold_until = 0
Discarding unused printer-state-changed event...
[Job 19] job-sheets=none,none
[Job 19] banner_page = 0
[Job 19] argv[0]="barcode"
[Job 19] argv[1]="19"
[Job 19] argv[2]="Rick"
[Job 19] argv[3]="Test Page"
[Job 19] argv[4]="1"
[Job 19] argv[5]="job-uuid=urn:uuid:9cc376d4-6d2a-348d-4e9c-c009daae4be9"
[Job 19] argv[6]="/var/spool/cups/d00019-001"
[Job 19] envp[0]="CUPS_CACHEDIR=/var/cache/cups"
[Job 19] envp[1]="CUPS_DATADIR=/usr/share/cups"
[Job 19] envp[2]="CUPS_DOCROOT=/usr/share/cups/html"
[Job 19] envp[3]="CUPS_FONTPATH=/usr/share/cups/fonts"
[Job 19] envp[4]="CUPS_REQUESTROOT=/var/spool/cups"
[Job 19] envp[5]="CUPS_SERVERBIN=/usr/libexec/cups"
[Job 19] envp[6]="CUPS_SERVERROOT=/etc/cups"
[Job 19] envp[7]="CUPS_STATEDIR=/var/run/cups"
[Job 19] envp[8]="PATH=/usr/libexec/cups/filter:/usr/bin:/usr/sbin:/bin:/usr/bin"
[Job 19] envp[9]="SERVER_ADMIN=root at miguel"
[Job 19] envp[10]="SOFTWARE=CUPS/1.3.4"
[Job 19] envp[11]="TMPDIR=/var/spool/cups/tmp"
[Job 19] envp[12]="USER=root"
[Job 19] envp[13]="CUPS_SERVER=/var/run/cups/cups.sock"
[Job 19] envp[14]="CUPS_ENCRYPTION=IfRequested"
[Job 19] envp[15]="IPP_PORT=631"
[Job 19] envp[16]="CHARSET=utf-8"
[Job 19] envp[17]="LANG=en_US.UTF8"
[Job 19] envp[18]="PPD=/etc/cups/ppd/barcode.ppd"
[Job 19] envp[19]="RIP_MAX_CACHE=8m"
[Job 19] envp[20]="CONTENT_TYPE=application/octet-stream"
[Job 19] envp[21]="DEVICE_URI=parallel:/dev/lp0"
D [03/Dec/2007:16:17:32 -0600] [Job 19] envp[22]="PRINTER=barcode"
[Job 19] Started backend /usr/libexec/cups/backend/parallel (PID 12068)
Discarding unused job-state event...
cupsdProcessIPPRequest: 8 status_code=0 (successful-ok)
Discarding unused printer-state-changed event...
Discarding unused job-progress event...
[Job 19] backendRunLoop(print_fd=5, device_fd=6, use_bc=0, side_cb=0x804956d)
[Job 19] Read 8192 bytes of print data...
Discarding unused printer-state-changed event...
Discarding unused printer-state-changed event...
Discarding unused printer-state-changed event...
[Job 19] Wrote 8192 bytes of print data...
[Job 19] Read 8192 bytes of print data...
[Job 19] Wrote 8192 bytes of print data...
[Job 19] Read 8192 bytes of print data...
[Job 19] Wrote 8192 bytes of print data...
[Job 19] Read 8192 bytes of print data...
cupsdReadClient: 14 POST /printers/barcode HTTP/1.1
cupsdAuthorize: No authentication data provided.
Get-Printer-Attributes http://192.168.2.158:631/printers/barcode
cupsdProcessIPPRequest: 14 status_code=0 (successful-ok)
[Job 19] Wrote 8192 bytes of print data...
[Job 19] Read 8192 bytes of print data...
[Job 19] Wrote 8192 bytes of print data...
[Job 19] Read 2366 bytes of print data...
[Job 19] Wrote 2366 bytes of print data...
Discarding unused printer-state-changed event...
PID 12068 (/usr/libexec/cups/backend/parallel) exited with no errors.
[Job 19] File 0 is complete.
[Job 19] Completed successfully.
Discarding unused printer-state-changed event...
Discarding unused job-completed event...
[Job 19] Unloading...
cupsdReadClient: 8 POST /printers/barcode HTTP/1.1
cupsdAuthorize: No authentication data provided.
Get-Printer-Attributes http://192.168.2.158:631/printers/barcode
cupsdProcessIPPRequest: 8 status_code=0 (successful-ok)

Is remote printing like this something that should work with this printer?