Scary df output

[Marius Amado Alves <amado.alves@netcabo.pt>]

I assume comand "df" is the one to know free disk space. It gives me 
this information:

Filesystem           1k-blocks      Used Available Use% Mounted on
/dev/hda1            -429168968127         1         0  49% /

according to which I have a negative number of blocks! Also, the columns 
seem to be disaligned because of that. Hand-correcting:

Filesystem           1k-blocks      Used Available Use% Mounted on
/dev/hda1            -429168968127     1         0  49% /

How should I interpret this?

Do I have space to install OpenOffice?

Thanks a lot.