I'm currently using ACT! Premium for Workgroups 2007 (9.0) (EX Edition) Version 188.8.131.52 English (Canada). In previous versions of ACT!, I was able to move multiple tasks at once by highlighting them, and dragging and dropping them into the mini calendar. This function is not available in my newer version. You cannot move multiple tasks (calls) in the Tasks, Calendar, or even Contact Activities this way at all. I'm really stuck.
I just bought ACT 2008 and I have the same problem. Act Support says that there is no work around for this. I have not converted my ACT 2000 database to 2008 yet, so I may just keep using ACT 2000. Have you found out anything new on this issue?