Please stop reporting problems with obsolete versions of stunnel. You should always upgrade to the latest stunnel and OpenSSL first, than repeat your tests and report a problem.
As the maintenance man of the 3.x branch (yes, some folks do use it still) the official stance is this:
* if it's a security bug, I'll patch it. * if it's a bug and you have a patch that works, I'll probably apply it * if it's a bug and you don't have a patch, I probably don't have the cycles to investigate it, sorry.
There's a 3.x wrapper that supports the old command line options.
4 is stable. 4 is good. And even. And the square of 2. What more could you need?