Clocks randomly forgetting trip mileage

[Jimp]

This has been happening on and off for a few weeks now. When it's a little chilly out my clocks randomly forget the trip mileage (the one on the right). The total miles done reading stays the same, as do things like time/distance travelled and average fuel consumption, it just randomly resets the trip mileage to 0. The very odd time the clock will go out either by an hour or a few minutes.
Has anyone encountered this kind of thing before? The clocks are Midline spec IIRC. The fact that just trip mileage and time change make me think that maybe the contacts for those switches are broken or loose or something. Anyone have any other ideas?

[david25]

I would try a scan (if you have cable and software) and a free Halfords battery check.

[Jimp]

Never thought of the battery. I'll whip out the multi-meter later on and check 

[david25]

Never thought of the battery. I'll whip out the multi-meter later on and check 

I found this page helpful http://www.sheffieldforum.co.uk/showthread.php?t=485529
for various info about battery voltages (about 1/3 the way down).