Battery problem w/ 755CDV

[hanks <hanks@cs.washington.edu>]

First my apologies, since I know this was discussed 
recently (and if anybody can point me to archives for this
list, I'd appreciate it).

I just bought two new batteries for my 755CDV, and the 
part number are both identical to that of my original.   

Neither battery seems to be recognized, however:  the fuel 
panel shows empty, and when I try to do the drain/recharge
cycle, I get a message saying "You must have a batter inserted."
Also, shortly after I disconnect the AC cord I get the warning 
sounds and sights indicating low battery.  

Both batteries seem to be fine, however, since I can run the machine off of 
both of them for a reasonable period of time.

Thanks for any help,
Steve.