It is possible to mine more than 12 tables at once. The trick is to create useraccounts under Windows XP, and datamine at the same time with all of them.
What you have to do in Windows:
1. Press "Start"->"Settings" and open the "Control Panel".
2. Doubleclick "Users" in the control panel.
3. Press "Create a new account" as seen in the following picture:

4. Insert a username and press "next".
5. Choose "Computeradministrator" in the following screen and create the XP-account.
Next step is to configure SpadeEye:
1. Copy your SpadeEye directory to a new directory (for example "SpadeEye2").
2. Run your copy of SpadeEye and set the "number of tables to open" to 4.
It is not possible to mine more than 4 tables, because we can not log in to the pokerclient twice with 1 Account.
Thats all.
Now you have to:
1. Run the pokerclient software under the first user.
2. Run SpadeEye under the first user and start datamining.
3. Switch to the second XP-account ("Start"->"Log off").
4. Log into your second XP-account.
5. Run the pokerclient software under the second user.
6. Run SpadeEye under the second user and start datamining.
Remark:
There is one small issue. If both copies of SpadeEye are setup to datamine the same limit, one can get the same hands twice,
because the current version of SpadeEye is not able to know which tables the other instance is mining at.
The best trick to avoid this problem is to specify different limits to mine. For example instance 1 could datamine $2/$4 SH and instance
2 could datamine $3/$6 SH (Just specify the limits under "Options"->"Limit"-tab).