My coworker's Windows 95 machine (at home over ISDN) triggered this
problem.  There was only about 14K in the send queue though.  I killed
his shell (he was rlogin'd to another box) and the machine was immediately
back on the network.  I'm running NetBSD-1.3.2/i386, on a P133 with
128MB RAM, a SMC EtherPower (de0), and several SCSI disks.
I've only seen this once though, haven't tried to reproduce it.

-Andrew
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Andrew Gillham                            | This space left blank
gillham@whirlpool.com                     | inadvertently.
I speak for myself, not for my employer.  | Contact the publisher.