Colibri logger errors?

Hello,

I have a Colibri logger (3.01) that on two consecutive flights gave me
faulty altitude logging (long periods of fixed altitude, and sudden spikes
to 50.000 ft+) Even though the flight was on April 1st, I tink there is
something wrong ;-) Also, it seems to be able to produce numerous short
flights of 4 seconds (this is also the recording interval), while lying
around on my dinner table ??

Has anyone out there seen such behaviour with a Colibri ? Could a fading
internal battery cause these sorts of trouble?

Thanks,
Lars Peder Hansen

DG-600 EE, Denmark.