Hello Glem,
I'm not sure if the Bios update will fix the IPMI Issue (don't know which specific issue are you talking about); you should try iLO (management) firmware instead.
ftp://15.193.112.23/ftp2/pub/softlib2/software1/pubsw-windows/p1113912866/v89582/SP62696.exe
cp021345.exe seems to be only for the x1600 and x1600 g2 so I don't think will work, even if different servers have same the same mother board probably the personality will change according to the serial/product number registered in the bios.
HP should have a Bios update for this server SE326m1 but as it's a SE Server (Special Edition) it's possible that you need special permissions to access documentation and downloads. Call HP and check it out.