First of all, a wrong version of dTa! 0.9.9.5 was published two times in the last few days, due to our and Mozilla Addon’s fault. If you downloaded it, please, install the correct package now available.
dTa! 0.9.9.5.1 fixes a critical bug which made the downloads not start, under certain conditions. It also solves a trouble which caused the failure of complete downloads on Linux and fixes “Server error” problems with downloads bigger than 4GB.
The update is strongly encouraged.