bug: QJackctl UI disappears

UI disappears:
===========
- open Qjackctl
- go to Options panel
- enter "a2jmidid -e" in "Execute script after Startup"
- tick box next to "Execute script after Startup"
Save settings
- start Jack
- open Patchage or Ardour2
- UI for QJackctl goes blank & can't click on any buttons in UI
- only way to get UI back is to shut down all apps and start again

alternately:
===========
repeat procedure WITHOUT entering "a2jmidid -e" command in "Execute script after Startup" field
and do not tick box
UI does NOT go blank

===================
my Linux audio perf config:
Lenovo Thinkpad T500
Mint 14 (MATE) i686 - 32 bit
kernel 3.5.0-48-generic
filesystem: ext3
jackdmp 1.9.9
Ardour 2.8.14-1
Ardour3 3.5.380-dbg
Pd version 0.43.4-extended
Presonus Firebox audio interface
Korg nanoKontrols x3
cpufreq-set - both cpu's are set to 2.27GHz

thanks!
kc