backup exec 11d powervault 124T does not recognize the 400GB tapes

Hi,

I just had to reinstall Backupexec 11D on my windows2003 server

but now the tape drive is not recognizing the full capacty of the LTO 3 tapes ( 400GB ) it is only seeing 35.5 GB

I have the latest service pack installed

and I told the divice wizard to use the symantec drivers

any other suggestions out there