samba - Jul 1999 - 2.0.x: terribly slow smbclient tar extension

Since the release of the first 2.0.x (jan1999) I noted that 
smbclient '\\server\share' -Tx filename.tar
was terribly slow.

smbclient '\\server\share' -Tc filename.tar
is as fast as 1.9.18.

If I use smbclient from 1.9.18 the performance is high (with the same target
pc).

These are some tests with:
- Win98pc
- lan 10Mbps
- samba-2.0.5-pre4/rh60
- a dir containing 1,2MB in 52 files

1) smbclient '\\server\share' -N -Tc filename.tar
4/5 secs (included name resolution time)

2) smbclient '\\server\share' -N -Tx filename.tar  (the tar file
produced at
point 1)
122 secs

3) cp from pc to samba (after having smbmounted the \\server\share dir)
4 secs

4) cp from samba to pc (after having smbmounted the \\server\share dir)
6 secs

Performance of copy/paste from win9x explorer is similar to that of smbmount.

Is there any explanation for point 2?

Thanks.

-- 
giulioo@tiscalinet.it