Has anyone experienced this problem? After getting my D300 back from Nikon for a B2 repair, I was using it out in Bishop, CA. It worked perfectly for several days then inexplicably when I pulled it out to use it, it wouldn't fire. Upon examination there was a dead battery symbol showing though both the enel-4 in the battery grip and the enel-3e in the camera were both completely fresh (this symbol showed whether the camera was turned on or not and there were no other symbols on the top lcd whether it was on or off). I pulled the also fresh enel-4 out of my D3s and swapped batteries. No change but the battery from the D300 showed full in the D3s. I removed the lens and reattached it, no change.
I put the D300 away and grabbed my D2h. Upon returning to the motel I removed the L-bracket and grip and removed both batteries. I waited a little while and reinstalled them. Presto, no more dead battery warning. The problem has not reoccurred.
I took the camera back to Nikon but since the problem is not there now, I doubt they will do anything.