Problem importing from Suunto HelO2

[Henrik]

Hi.

I have a Suunto HelO2, and imports via libdivecomputer (MacDive) only 
work some times.  It seems that the evening after a dive I cannot 
import, while on the next day it works.

Here's a log:

henrik at kollaps:~/Downloads$ ./vyper2  /dev/tty.SLAB_USBtoUART
DATETIME 2012-04-21T16:37:37Z (1335026257)
REVISION 5126ef389a0b8983752008568cf26bdbd46b3257
DEVICE=/dev/tty.SLAB_USBtoUART
suunto_vyper2_device_open
Configure: baudrate=9600, databits=8, parity=0, stopbits=1, flowcontrol=0
Timeout: value=3000
DTR: value=1
Sleep: value=100
Flush: queue=3, input=0, output=0
device_version
Sleep: value=600
RTS: value=1
Sleep: value=6
Write: timer=8, size=4, data=0F00000F, remaining=0
RTS: value=0
Read: timer=3001, size=0, data=, remaining=0
../../source/src/suunto_vyper2.c:193: Failed to receive the answer.
Sleep: value=600
RTS: value=1
Sleep: value=6
Write: timer=8, size=4, data=0F00000F, remaining=0
RTS: value=0
Read: timer=3001, size=0, data=, remaining=0
../../source/src/suunto_vyper2.c:193: Failed to receive the answer.
Sleep: value=600
RTS: value=1
Sleep: value=6
Write: timer=7, size=4, data=0F00000F, remaining=0
RTS: value=0
Read: timer=3001, size=0, data=, remaining=0
../../source/src/suunto_vyper2.c:193: Failed to receive the answer.
../../source/examples/suunto_vyper2_test.c:85: Cannot identify computer.
suunto_vyper2_device_open
Configure: baudrate=9600, databits=8, parity=0, stopbits=1, flowcontrol=0
Timeout: value=3000
DTR: value=1
Sleep: value=100
Flush: queue=3, input=0, output=0
device_version
Sleep: value=600
RTS: value=1
Sleep: value=6
Write: timer=8, size=4, data=0F00000F, remaining=0
RTS: value=0
Read: timer=3001, size=0, data=, remaining=0
../../source/src/suunto_vyper2.c:193: Failed to receive the answer.
Sleep: value=600
RTS: value=1
Sleep: value=6
Write: timer=8, size=4, data=0F00000F, remaining=0
RTS: value=0
Read: timer=3001, size=0, data=, remaining=0
../../source/src/suunto_vyper2.c:193: Failed to receive the answer.
Sleep: value=600
RTS: value=1
Sleep: value=6
Write: timer=8, size=4, data=0F00000F, remaining=0
RTS: value=0
Read: timer=3001, size=0, data=, remaining=0
../../source/src/suunto_vyper2.c:193: Failed to receive the answer.
../../source/examples/suunto_vyper2_test.c:45: Cannot identify computer.

SUMMARY
-------
test_dump_memory: Timeout
test_dump_sdm:    Timeout


I've tried switching USB ports and rebooting the machine, without 
success.  I use MacOSX Lion on a 2010 MacBook Pro.

Best regards,
Henrik