Shopping Cart can't update

I am using the latest version of Event Booking (1.6.10) and my client pointed out to me that she can't update her shopping cart. Upon verifying it is not working and I've search through this forum and saw where there was a fix for this problem in Joomla 1.5 but it's still showing up in the latest of Joomla 3.4.0 (Which I am currently running)

Any help on this would be appreciated.

Cannot update ? Could you please give us more information ? Maybe it is because you set "Prevent Duplicate Registration" config option to Yes and registrants could not change quantity ? If so, please go to Events Booking -> Configuration, find the config option "Prevent Duplicate Registration", set it to No and it should work well

Tuan