Anyone had this happen on *ist-D?

[Tiger Moses]

Initially the only batteries I put in were 4 NiMH in the battery pack and 
left camera empty...everything normal.

Then I put another set of NiMH in Camera (so now 8 batteries).  Shooting - 
everything normal...but come time to download,
get battery depleted message.

Remove either set, everything fine.  Have sets, get battery dead and camera 
will even shut off, though neither set is dead, or even near dead!