how can I troubleshoot ulpt0 causing errors with my ural0?

(If you have a suggestion for a tech-* list to also post at, please let me 
know.)

I have been using ural for over a year.

ral0 at uhub2 port 1
ral0: Cisco-Linksys Wireless-G USB Network Adapter, rev 2.00/0.04, addr 2
ral0: MAC/BBP RT2570 (rev 0x03), RF RT2526
ral0: 11b rates: 1Mbps 2Mbps 5.5Mbps 11Mbps
ral0: 11g rates: 1Mbps 2Mbps 5.5Mbps 11Mbps 6Mbps 9Mbps 12Mbps 18Mbps 
24Mbps 36Mbps 48Mbps 54Mbps

Today, I plugged in my printer via USB.

ulpt0 at uhub2 port 2 configuration 1 interface 0
ulpt0: Brother HL-5150D, rev 2.00/1.00, addr 3, iclass 7/1
ulpt0: using bi-directional mode

My networking started hanging a lot. I looked at netstat -i and saw a 
bunch of "errs".

netstat man page says:

	BUGS
     		The notion of errors is ill-defined.

Why?

Watching "netstat -I ral0 -w 60" for about an hour showed the input errors 
are staying the same, but the output errors are growing from 186 (where I 
started watching) to 224 errors. My network is hanging at same point when 
that goes up. I don't recall having any errors before (even though my 
networking would be up for over a week at a time). It sometimes is just 
slow and sometimes hangs for more thanm 5 seconds.

I powered down my printer:

ulpt0: at uhub2 port 2 (addr 3) disconnected
ulpt0 detached

And now about five minutes later no more "errs" (with ulpt0 disabled).

Any suggestions on how I can troubleshoot this? (Anything to look at with 
"systat vmstat" for example??)

This is NetBSD/i386 3.99.24. I will upgrade soon to see if this fixes it. 
(Nevertheless, I'd like to learn some troubleshooting techniques for my 
education too.)

  Jeremy C. Reed