try adding fifo disabling code in com.c in comclose()?

i think they'll get turned back on by comparam()

bus_io_write_1(bc, ioh, com_fifo, 0);
at line 649 of com.c v 1.77

comparam may not do the trick and I'm pulling ALL of this out
of my ass so don't even start unless you like this sort of gory
poke and recompile and reboot stuff.

-j