First of all, you didn't mention what's the problem you are having with latest avast! program build. Turnip isn't a part of avast!, that's for sure... how it grew on your head, who knows, because you never mentioned what was the real problem you have experienced with release 4.6.618.
Second of all, 4.6.618 is BETA release. No one is forcing anyone to download it and install it. Many of us are here to give avast! technical support as well as to test BETA releases. We use that at our own risk. We are well prepared for problems that can occur, therefore we have our system backups (image files) ready.
Downloading and installing a BETA is not a must. If you think you can handle possible issues with newest BETA release, and you decide you'll go with BETA, it's your own decision, your own way. BETA means that this release is still under intensive construction and it's a TEST release, even though Alwil Software never failed on us. Testers chose to install and test beta versions voluntarily, accepting all possible situations after installing test version. So far I haven't noticed any single problem with 4.6.618.
Cheers !