Problem with Zones Table Rate shipping calculation

Please help! I posted this in the Zones Table Rate thread 4 days ago, but haven't received any replies (maybe that's just because it was a holiday weekend in the US). So, I apologize for the crosspost.

I'm using Price mode and I'm using the following rate for Zone 1: 100:10,100000:10%. My understanding is that this rate should charge $10 for anything up to $100 and then 10% for anything over $100. This will give me a minimum shipping charge of $10. I've configured 4 zones and it seems to be working OK except for one problem.

The system charges 10% shipping for all orders, even those under $100. I've tried a whole lot of different combinations (including using only flat dollar amounts instead of a percentage), and it always charges the LAST number in the list. So, if I use 50:5,250:10,500:20, I get a shipping charge of $20 for ANY order amount. This is true for all of my zones!

Anyone have any ideas on what I'm doing wrong?

Am I posting this in the wrong forum or have I violated some rule for posting or asking questions? I don't understand why no one will respond to my question. I know that everyone is working on a volunteer basis and I appreciate that very much, but can anyone help please? Or is there some way to receive paid support?