there is the option to hide tasks in the main task tree. I use this to hide tasks I no longer work on (don't want to delete them but keep the data for reference). It would be very convenient if the "Create new time slot" dialog would respect the "Hidden"-flag in its "Change task" combo box as as well. This would restrict the list to the visible (=active) tasks only and make picking the right task much easier.
Thanks a lot for TST - it is a great tool and your support is fantastic! :-)