I have both a LRTPT 2.5 and 3.0, both are running fw 29. The 3.0 works perfectly as does the 2.5 but it always asks me to set the date and time when its booted after being off for a few hours (The 3 never asks me to set it). Any ideas ?

The Battery of the real time clock is low. Please exchange it. See the second last entry in the faq: https://lrtimelapse.com/lrtpt/faq/

Doh, sorry I should have searched first :-)