So here was how i resolved this and some suggestions for Sandisk/ panasonic.
So the senarios is as follows, the video recorder did not switch off on a couple of occasions when it was put back in the bag and recorded 2 massive recordings. My thought are that this corrupted the disk header.
Whenever it was put the SDram in the video camera , the camera flashed an error with card. When i placed it in a Windows system i requested a disk format.
So on advice form one of the techies at work, i used Linux, yes, linux.
i created a bootable USB stick from this web site http://www.sysresccd.org/SystemRescueCd_Homepage
Then booted from the USB stick on a relativley new laptop (i.e. newer SD card probbaly)
Once the linux system had booted and i put the card in the laptop card reader, linux was able to read the full disk.
Why linux reads microsoft disk formats better than microsoft i cannot explain.
I would suggest that Sandisk create a Test Case to check what happens when sandisk extreme attempts to full the whole drive and in particular using a Panasonic Video Recorder.
I hope this helps others.
all the best
ps - Sandisk /RescuePro CD (not free) i downloaded these tools and was unable to get the application to read the drive.
There are several versions and was kindly pointed by LC technologies to various utilities.
Im still shocked at how linux was able to read the disk without a problem.