Battery discharge problem ( battery ok )

[marcfair]

I've been having problems with my S2 elise battery discharging from 12.8v to 10v in around 4 days, had a few batteries on etc.. as the problem has been occuring over the last year. did a multimeter test today

Multimeter in series with battery, readings as follows;
25mA with nothing switched on, then when immobliser kicks in i am getting readings of 25 to 60mA fluctuating (pulsing on meter). Removed/replaced every fuse 1 at a time and the reading never changed.
Could it be a duff imobliser? i'm assuming the imobliser has a battery back up somewhere?
i've done a load test on the car battery (which is a month old) and this seams to be fine