[cups.general] IPP printing failing

[Romain Riviere]

Hello list,

I am looking for help regarding the following problem.
I have setup CUPS v 1.2.10-r1 on a Gentoo-running Mac mini (ppc).
Locally printing with lpr for instance works well. But printing over  
IPP yielded strange results : CUPS reports that printing is complete,  
but the printer doesn't twitch.
Log sample from a non-print :

I [02/Jul/2007:20:41:31 +0200] Job 14 queued on  
"HP_psc_1200_series_USB_MY47EG30BMT0_HPLIP" by "smokey".
I [02/Jul/2007:20:41:31 +0200] Started backend /usr/libexec/cups/ 
backend/hp (PID 23189) for job 14.
D [02/Jul/2007:20:41:33 +0200] PID 23189 (/usr/libexec/cups/backend/ 
hp) exited with no errors.

I snipped the enormous amount of logs in between these lines. If more  
logging is needed to diagnose the problem I'd be glad to provide them.
I might add that using the USB backend from CUPS and it hasn't helped  
either. The HP backend is provided by hplip 1.7.4a-r1

So obviously CUPS is getting data from my laptop (which was a first  
hurdle), but then that data seems to vanish somewhere ...

Thanks for any light you can shed on this issue.

Best regards,

Romain Riviere