Triple booting Leopard 10.5.7, Vista, And ubuntu on Dell inspiron 1525

[WhYSoOoSerious]

hey folks):P

i need help

i have dell inspiron 1525 , i am runnin leopard 10.5.7 and vista through chameleon bootloader

my hard disk is 250 giga ( 200 giga for vista, 20 for leopard, 10 giga as recovery and 100 mega as dell disk utility)

i tried to triple boot but i faced a prob

i simply do the step[s till i reached to the partition manager in step 4

i deleted the recovery partition( i have it backed up ;)) then i created anew extended partition and under that i created 2 partition one for ubuntu as ext3 with ( / ) around 9 giga and the other as swap one around one giga

after that when i reached the final step i hit advance to install the grub in the ubuntu partition to run it smoothly through chameleon boot but when i hit install and about 30% done, bam an error massage pop up and said " cd or dvd error.....etc plz bur it again or diskerror....etc"

so i burned it again and tried it out in vmware and worked well and i did the same as i mentioned about 5 times and always stuck at 30% and error

so guys help:p

[WhYSoOoSerious]

is any one have any idea about my problem????