PHP session issue

Hi there,

I have a bizaare problem:

Actually a PHP session issue but if there are any quick suggestion it would
be very much appreciated
I've got php running on a win 2k machine and IIS
I am authenticating access to admin pages via an operator variable which
must be set and is registered with the current session
If I access the pages on the localhost machine it works fine:
I login it jumps to the required page and grants access because the username
and pasword were validated against the PostgreSQL database and the operator
variable was set accordingly

But if I go through the same proceedure from a different computer win98
machine it doesn't grant me access to the page it jumps to the right page
but returns me to the login page with a "NO ACCESS" error as it should if
the operator id is not set

the weird thing is when I look at the sessions that get created:
the operator variable did actually get set BUT for some reason when it jumps
to the required page after the login it creates a new session file with no
entries at all - blank
the old one actually contains the set operator variable but gets disregarded
because the page now looks at the empty session and therefor denies access??

I have no idea what is causing this
anybody have any ideas? would be greatly appreciated

thanks, Peter