Sencha Cmd hangs/freezes w/o any output

Today I've installed the 64 bit Linux version of Sencha Cmd on a Linux Mint 16 workstation. The installation process was successful, but when I try to start Sencha Cmd by typing "sencha" (w/o any options) at the cmd prompt, the program starts (cursor jumps to next line) and then hangs without any output.

The JRE is an OpenJDK 1.7.0_51 (OpenJDK Runtime Environment IcedTea 2.4.4), Ruby is a v1.9.3p194, Sencha installation path was ~/bin/ (as suggested by the installer).

I've also tried a few older versions of Sencha Cmd, but with the same results.

Any suggestions?

thx in advance,

boman