Hm, it could be because of the outdated SSL stuff on Stable.
Until you fix it, you could make a shell script that automates downloading the virus definitions and moving them over.
3.0.6 is also quite old so if you do want a modern system there's the Beta version. It's less polished than the Stable one though, but you can also customise the E16 to be pretty great with @triantares' guide Tutorial on handling E16 by customizing the desktop.
