You do have cards in your trade list...I just confirmed, but you might have your transaction options turned off...follow these steps:
1. Click on your profile name MoTown Cards in the upper right corner of the screen.
2. Select "Profile" from the drop-down list.
3. Towards the top click on "Settings."
4. Click on the link for "Transactions."
5. Next to the top option you will see "Allow other members to send you transaction proposals...make sure this is on Yes
6. Next to the other option" Allow other members to match their Wantlist to your Collection...make sure this is on Yes
(I believe step six is the issue.)