samba - Oct 1997 - Win95 displays program icons for *some* Samba drives incorrectly

I have two machines, both running samba 1.9.17p2...one SunOS, one
Solaris, and a Win95 box mounts drives from both. Each have
essentially identical smb.conf files, and in particular both have 
        preserve case = yes
        short preserve case = yes
        case sensitive = no
The main differences is that the SunOS box is set up with domain
logons = yes and security = user. The Solaris box has security server and points
at the first machine as its password
server. 

The problem is this: If I copy Windows .EXE files onto the Solaris box,
then browse the directories, they appear with an MS-DOS .EXE icon
instead of their correct icons, ditto if I try and create a shortcut
on the desktop to such a program.  This behaviour doesn'r happen with
the SunOS box...all icons display just fine.  There is obviously some
caching going on in Windows...if I do something drag charmap.exe off
the C: drive and drop it in a folder on the Solaris box, it appears
with the correct icon until I hit View|Refresh in that window, when it
changes to the MS-DOS icons again.  This behaviour does not happen on
the SunOS box. Both network drives are reconnected at logon, both
files end up with the same modes and timestamps on the servers, eg 
-rwxr--r--   1 pete     user       14752 Aug 24  1996 CHARMAP.EXE
and I even went to the trouble of system call tracing the Samba
processes on both machines whilst doing a View|Refresh...they perform
equivalent sequences of syscalls, stat the same files and even seem to
return the same answers to the Windows box (I only have truss on the
Solaris box so couldn't see the full data that was written back).

An extensive web search trying to determine what factors make Windows
95 decide it should display a generic program icon rather than the
icon from the program file itself didn't turn up anything, perhaps
someone here could help me out with that, which should help me debug
the Samba config.

Actually, while I was writing this I did find one difference between
the two shares...the Solaris share is rather large (8GB). If I
right-click the share in My Computer and select Properties, it shows
up as a 1.99G disk with 0 bytes used --- surely this couldn't be a
factor? 

Pete.