droid 2 2.3.20 is newer than 2.4.5 that the r2d2 has... the kernel and the baseband version is newer on the droid 2 update.. 2.4.5 has the same kernel and baseband as the stock 2.2.2 droid 2 without the new update
if your rooted i know the fix
you need to reinstall batteryreport.apk either through terminal emulater or root explorer and set permissions it constantly screws up on my rom i made a script to fix it,that tells you how bad it is.