ubuntu Installer is not detecting my partition

Hi frnds,

   Few months back i installed ubuntu 5.10 and everything was working fine.Then i thought to upgrade it to either 6.06 or 6.10. since then things are getting worse. I downloaded 6.06 LTS and 6.10 using torrents frm different sources. I have tried more than six or seven times to upgrade using different methods like using update manager in 5.10, Live cd or "alternate cd". But each time i'm facing different problems. First, when i used live cd to install 6.06 it got strucked at "gparted" n i waited for more than one hr but nothing happened. Then i tried with 6.10 live cd. In this after installing base, a blank screen appeared. Now i have downloaded alternate cd but now they are not detecting my Windows partitions. Its showing single unused space, and asking me to partition my whole HDD when i select "manually edit partition".To make the thing still worse the ubuntu 5.10 installation cd which was working fine with my pc, is also not detecting my partitions.

   I'm using dual boot win xp sp2 and ubuntu. 120GB western digital HDD. And BTW all my filesystem are FAT32.

  I don't know watz happening with me...... plz help me????