Just tried to merge my accounts. Took almost 8 times before went pass step 3, but got the above error at the very last step.
-- Added --
Finally by keep trying, on the ~20 times, my accounts merged. The LT balance is correct, even though the Confirmation page was incorrect as mentioned by others above.
+1 for the "Added" section.
Same experience in that LT nights from both programs were accurate in the last step (but not initially). There also seemed like there was a timeout going through the process - I was flipping back and forth between here and the merge site and eventually had to start over again.