CMUBox `Timestamp Trouble'

1
Hi there,

I am using the CMUBox() function to get input from a PST serial response box. We're running Ubuntu on the machine, and using Octave to run Psychtoolbox. I keep getting the Timestamp trouble!! error. My code is below:

octave:1> bh=CMUBox('Open','pst','/dev/ttyS0')
CMUBox: Using PST serial response button box!
bh = 1
octave:2> evt=CMUBox('GetEvent',bh,1)
CMUBox: GetEvent: Timestamp trouble!! Delta 23624.439001 msecs, ScanInterval 0.002000 msecs.
evt =

scalar structure containing the fields:

time = 1.3760e+09
streamTime = 1.3760e+09
state = 1
trouble = 1
deltaScan = 2.0000e-06

octave:3> CMUBox('Status',bh)
ans =

scalar structure containing the fields:

useBitwhacker = 0
Streaming = 1
type = 3
ftdiusbserialtype = 0
norelease = 0
portName = /dev/ttyS0
port = 0
dt = 0.0013176
oldState = 1
baseTime = 1.3760e+09
olderr =
oldTime = 1.3760e+09
tTrouble = 1
deltaScan = 2.0000e-06
skipped = 0

Things I have checked/tried:
- the PST box is definitely set to 800 cps, and 19200 baud.
- running as administrator doesn't help.
- setting Priority to 1 with Priority() doesn't help
( here's my script for that, in case I didn't do it right:

octave:4> oldPriority=Priority(1)
PTB-INFO: Display ':0' : X-Screen 0 : Assigning primary output as 0 with RandR-CRTC 0 and GPU-CRTC 0.
oldPriority = 0

)

Any advice would be greatly appreciated!
~Claire