samba - Sep 2002 - Force user does not work if connecting to more than one share fro m a PC

I am trying to simulate functionality that was provided by Reflection NFS.
With this product a user can connect to two shares on the same server with
different user authentication.

I have tried to use Samba to achieve the same effect with no success.

If I try the following :

net use X: \\server\share1 <\\server\share1>  /user:user1
net use Y: \\server\share2 <\\server\share2>  /user:user2

When mapping the second drive I get the error message 

'The credentials supplied conflict with an existing set of credentials'

I understand this is a limitation imposed by Windows NT.

So I have tried to use the 'force user' option on each of the two
shares.

[share1]
    force user = user1
    path = /usr/data1
[share2]
    force user = user2
    path = /usr/data2

When I map the second share on the client it appears to force the user from
the first mapping not the second.

Any ideas how I can get around this.

Samba version : 2.2.2
Platform : Solaris (SPARC)

Regards

Mike Phillips