try running it from the command line (xterm or rxvt) to see what the issue is. however, bochs is notoriously slow (and basically unusable IMHO).

other options:

you may want to try running your apps in wine (very hit or miss).

QEMU is not a bad open sauce substitute for an virtual machine, performance is much better than bochs. However, with VMWare player and server available for free (but not open source) this is going to be your best bet. Commercial speed at the right price.

With KNX 4.0 you have union file system, so you could just install them on a live CD prior to remastering.

good luck.