Relationships not working - sometimes

[bigmac]

I have 2 product databases. One in Filemaker server 9, and one MySQL Server on my web. They are connected via ODBC and a SSH tunnel. Works great.

The web database has approx 3000 products, and the filemaker database 1500 products. Some of these products are the same, ie has the same part number.

What I want is the following:

In the web product part list, I want to show wich parts are "in stock" in my filemaker system. I use the relation partnumber=partnumber between the 2 databases. Works great.

In the filemaker product part list, I want to show wich parts are "in stock" in my web product part list. I use the same relation as above, but it only works like 50% of all the products.

So, it works 100% one way, but only 50% the other way. I'm going crazy, and my developer can't understand it either.

Here are 2 windows on top of eachother. Partnumber leftmost column. In the bottom column, it's supposed to say "1" in the ":..." column, just as it says 1 on "stock_type" in the top window column.

Relation

Relation again

Please help...