Hard Disk Needs Reinitialisation

[ThinkFree]

Download Fedora11 32bit live cd and booted it using a pen drive. Within 70 seconds(after powering on), the boot process was over and I could see GUI. Now the problem is that when I start the installer and click NEXT, it shows a warning saying hard disk needs reinitialisation. If I ignore this and go to partition step, I don't see any existing partition, whole hard disk is shown as free space. Anyone having any idea what it is? Also, GParted in Fedora 10 wasn't able to detect any partition and showed the same disk layout(ie free space only). There is one NTFS partition, one for swap and 4 ext3 partitions on the disk and are working fine .

[ThinkFree]

No one?

The partitions were working while I was using fedora11 live from pen drive, but when I restarted the computer, all the partitions disappeared. Now no partition is left and I only see disk as sda