I have been testing this and I have found a quick solution.
After Nettalk 8.47 the SSL Open source DLLs were updated to version 1.02a
These seem to be the problem.
I have replaced the DLLs from Nettalk version 8.46 and the server does not crash.
ssleat32.dll , libssl32.dll and libeay32.dll (older open source version 1.0.1.12)
Hope this helps
Cheers
Vinnie