I had a similar problem on Monday where the system froze on sending the final statement. No solution was offered, although it may have been that the system went down during the Send Email operation. The screen remained frozen for pretty much the rest of the day, even after the system came back up.
yep i had this for a while too. have you checked the options in the company preferences screen? go to "edit-preferences-online-company preferences" there is a little check box called "display each email when sending more than one" make sure this is not checked and then all emails will shoot off as a batch. hope this helps