I'm ahead of you on this
I spent last night making the server try to connect to itself every minute to detect when something goes wrong so it can restart itself. I also changed the watcher program to detect a locked up server better. I'll roll those and a few more changes out soon.
I've had another person report issues with drFTPD over SSL getting that "Unexpected end of handshake data" message as well. That log message info is new though and almost certainly related. If you can connect to the drFTPD site and download from it directly what does the client say the encryption mechanism chosen was? I.e. was is aes256, aes128, or something else. I am aware that some Java implementations have a crippled crypto suite installed by default to use short keys and I wonder if that could be part of the issue.
I'm also not convinced that OpenSSL v1.0 isn't slightly different than older beta releases based on comments elsewhere.
Do any transfers from that site work, or does it randomly not work?