Kernel 2.2.18: Protocol 0008 is buggy

[Ivan Passos]

Hello,

I have a customer who's getting tons of these msgs in his LOGs:

kernel: protocol 0008 is buggy, dev hdlc0
kernel: protocol 0608 is buggy, dev hdlc0

The msg comes from net/core/dev.c, and this device is using the Cisco HDLC 
protocol in drivers/net/hdlc.c . However, AFAIK, 0008 and 0608 represent
IP and ARP (respectively), not Cisco HDLC. So ...

What I'd like to know is: what exactly causes this msg?? It seems that
it's printed when someone sends a packet without properly setting 
skb->nh.raw first, but who's supposed to set skb->nh.raw?? The HW driver??
The data link (HDLC) driver?? The kernel protocol drivers? How should I go
about fixing this problem, where should I start??

I'm at a total loss here. Any help would be really appreciated.

Later,
Ivan