Samba4 panic action

[steve]

Version 4.1.0pre1-GIT-957f9fa
Hi
Accessing shares on the s3fs server from a w7 client hangs with this:

/usr/local/samba/sbin/smbd: Freed frame ../source3/smbd/process.c:3617, 
expected ../source3/smbd/nttrans.c:1910.
/usr/local/samba/sbin/smbd: PANIC (pid 4866): Frame not freed in order.
/usr/local/samba/sbin/smbd: BACKTRACE: 15 stack frames:
/usr/local/samba/sbin/smbd:  #0 
/usr/local/samba/lib/libsmbconf.so.0(log_stack_trace+0x2b) [0xb710b76a]
/usr/local/samba/sbin/smbd:  #1 
/usr/local/samba/lib/libsmbconf.so.0(smb_panic_s3+0x82) [0xb710b599]
/usr/local/samba/sbin/smbd:  #2 
/usr/local/samba/lib/libsamba-util.so.0(smb_panic+0x2a) [0xb76feea2]
/usr/local/samba/sbin/smbd:  #3 
/usr/local/samba/lib/libsamba-util.so.0(+0xab35) [0xb76f0b35]
/usr/local/samba/sbin/smbd:  #4 
/usr/local/samba/lib/private/libtalloc.so.2(+0x2876) [0xb737f876]
/usr/local/samba/sbin/smbd:  #5 
/usr/local/samba/lib/private/libtalloc.so.2(_talloc_free+0xe5) [0xb7380a7a]
/usr/local/samba/sbin/smbd:  #6 
/usr/local/samba/lib/private/libsmbd_base.so(smbd_process+0x12be) 
[0xb74b7feb]
/usr/local/samba/sbin/smbd:  #7 /usr/local/samba/sbin/smbd() [0x8050b50]
/usr/local/samba/sbin/smbd:  #8 
/usr/local/samba/lib/libsmbconf.so.0(run_events_poll+0x64b) [0xb712770c]
/usr/local/samba/sbin/smbd:  #9 
/usr/local/samba/lib/libsmbconf.so.0(+0x3a99b) [0xb712799b]
/usr/local/samba/sbin/smbd:  #10 
/usr/local/samba/lib/private/libtevent.so.0(_tevent_loop_once+0xdd) 
[0xb7172544]
/usr/local/samba/sbin/smbd:  #11 /usr/local/samba/sbin/smbd() [0x8051779]
/usr/local/samba/sbin/smbd:  #12 /usr/local/samba/sbin/smbd(main+0x175d) 
[0x805303b]
/usr/local/samba/sbin/smbd:  #13 /lib/libc.so.6(__libc_start_main+0xf5) 
[0xb69dd3d5]
/usr/local/samba/sbin/smbd:  #14 /usr/local/samba/sbin/smbd() [0x804c391]
/usr/local/samba/sbin/smbd: smb_panic(): calling panic action 
[/bin/sleep 999999999]

I've tried restarting both S4 and the client. Any ideas?
Thanks,
Steve