reverse proxy shopping system

[Isaac Hailperin]

Hi,

I have several shopping systems running on apache that I would like to 
proxy with nginx. In general it works fine, but in some shops I have the 
problem that when I add items to the shopping cart and then proceed to 
view the shopping cart, the cart seems empty. Without the proxy it works 
just fine.

So I was wondering how I could debug this. Any hints on how to takle 
this so I have a clue on how I could configure nginx so that it works 
would be apreciated.

Isaac