startup says invalid floating pt operation, no menu display

if i install and run portableapps.com platform on an external disk (NAS, 2tb*2 raid1 mirrored) during startup it displays "invalid floating pt op" in modal dialog with OK button. the menu does not display, though hovering over taskbar icon shows menu.

when i copy that same installation (file tree) to my c: disk, it works fine. haven't tried usb flash disk yet.

since it's portable, it should run from any disk, n'est-ce pas?'t
maybe it has a problem on a disk accessed via the network?

latest 11.2 version (haven't tried beta v12).
win8, laptop toshiba satellite u845t, 1 yr old, 6GB ram,
500gb c: disk, 32GB ssd cache, i5-3337u processor quad core 1.8 GHz boosts 50% to 2.7. 64bit chip & win8. happens with a bunch of installed apps. happens without any installed apps. happens if i install on C: and copy to NAS, or vice versa. NAS is mounted as z:. reproducible. haven't tried on second pc 'cause don't have.

would be very useful to run from shared network server.