Crash while sending ZFS file system

[Willem Jan Withagen]

Hi,

I've got this relatively "old" (somewhere from around 8.0) ZFS filesytem 
that I'm trying to send to a new server.
Given the ae, it could be very well that these is something off on the pool.

But it core-dumps on:
zfs send -v -R zfsraid at box | mbuffer -4 -m 100M -O box:5555
........
send from @ to zfsraid/ezjail/nameserver at box estimated size is 245M
send from @ to zfsraid/ezjail/newjail at box estimated size is 1.30M
send from @ to zfsraid/obj at box estimated size is 4.80G
send from @ to zfsraid/sonycam at box estimated size is 5.22M
Assertion failed: (progress), file 
/usr/srcs/src9/src/cddl/lib/libzfs/../../../cddl/contrib/opensolaris/lib/libzfs/common/libzfs_sendrecv.c, 
line 1316.

The FreeBSD version is:
FreeBSD zfs.digiware.nl 9.2-PRERELEASE FreeBSD 9.2-PRERELEASE #242 r253371

Now I can send some of the snapshots that are mounted on home.
Just not the whole set of snapshots.

It bombs out even still during the listing of all snapshots to send.
If I look at the code it asserts that progress needs to be made.
If this is not the case the assert is activated.

Any suggestions as to how to fix/debug this?
It generates a coredump

Regards,
--WjW