clip plus: USB connection fails on dev:20140403-580104d build

[murmel]

the USB connection fails either with message:

undefined instruction
pc:0000003c sp:2fffff?
bt end

no RESET nedded.

or an other message:

data abort at 3003af4?
FSR 0x8
(domain 0, fault
adress 0xdeadbef3
pc:3003af48 sp:300b56?

RESET (10-15sec POWER) needed

[murmel]

these connection fails on the daily build happen either using WIN7 or linux as a host.
what can I do to figure out more information about?
knowing only pc/sp values is quite useless - they always the same.

one question to the cracks: is it possible to sniff the USB-handshake via the linux host?
or is a standardised checking pattern available - like
- power off -> connect
- power on - stop playing -> connect
- power on - while playing -> connect
- reset befor connectin
- etc.

I'm able to sniff the electrical signals (logic-analyser/oscilloscope) and can make pictures from it - if this could help

murmel