Thank you for your post into the forum.
I am not aware of any changes between version's 9 and 10 that would cause SQL Data Compare to pause or stall whilst reading DDL Triggers.
A Support colleague has compared the source code in V9 and V10 and there have been no changes to the code that reads in the DDL Triggers.
A support call has been created for you, the call reference number is F0058732.
Can you please turn on the SQL Data Compare Logging and send to us the log file? To turn on the logging, click on the SQL Data Compare icon immediately above the File menu. Change the minimum logging level to verbose if not already set. Run the comparison, when the results are displayed, obtain the log file and send an e-mail to email@example.com
with the above call reference number in the subject field of the e-mail with a copy of the log file attached?