Why are browsing samba shares from Ubuntu (Nautilus) so much slower than browsing from Windows

I have a samba share over the a vpn server. Browsing the share takes 60 times longer from Ubuntu than it takes from Windows.

From a Windows 7 Virtual Box (and any other machine in the shop) it takes 3 seconds for a folder with 1000 files to appear.

Clicking on the same folder from Nautilus it takes over 3 minutes before the files show.

The network is the same. The only difference is browsing from Ubuntu vs browsing from Windows.

This is the /etc/fstab entry from the Ubuntu machine:

//myserver/officeshared /mnt/myshare cifs noauto,username=myname,uid=1001,file_mode=0660,dir_mode=0775,noexec,credentials=/etc/smbpassw 0 0

I'm sure the problem is Nautilus and not ubuntu because I can get a file listing in 3 seconds with:

time ls /mnt2/mckserver/McKelvey/ > ~/filelist.txt

Output:

real    0m2.223s
user    0m0.004s
sys     0m0.007s