I am just getting off the ground, experimenting with multiple installations on both Windows and Linux... since apparently PTT is broken in Linux and there is nothing I can do about it!
I can run WSJTX 1.1 in Ubuntu just fine, with the exception of my separate serial PTT not working. It decodes perfectly well. Then, on the same computer, attached to the same radio, reboot to Debian/Virtualbox, running a Windows 8.1 VM... where WSJTX 1.3 is installed.
There, PTT works fine, audio looks the same on the waterfall, but NO DECODE no matter what I try. Clock sync is perfect. I have done my homework, and read hundreds of posts here and elsewhere. What am I missing?