ubuntu , usb booting , home directory error

[savalan86]

hi
i install ubuntu 8.4 on a usb flash disk , in first time system work currectly and without any errors . but after one restaring , when loading desktop show an error box , see the photo :

http://i38.tinypic.com/21klzsn.jpg

after close this box , show this error box :

http://i38.tinypic.com/jgih5x.jpg

and after close this box , show this error box :

http://i33.tinypic.com/29vjdzq.jpg

and after close this box , show login window ( with a few difference ) :

http://i35.tinypic.com/hwalmq.jpg

and after this section , repeat above parts , and my desktop not load ...

i install ubuntu 7.4 in usb flash with different way , but still show same error for me ??!?

please help me
very thanks !