On a specific set/pair of TB50's on my I2 I cannot properly shutdown the I2 but must physically eject the two batteries to effect a shutdown. This is unique to only one-pair of batteries, the other pairs all shutdown fine. I've rundown the batteries (angel) and recharged, all operations of the I2 are working except shutdown. I can find no information on this? Not a showstopper of course as ejection works, but am concerned about issues that may not be forthcoming with this happening. TB-50s less that 15 cycles.