[Koha] problems decompressing file koha-3.00.04_fixed.tar.gz

Hello, I'm having trouble decompressing the file downloaded from http://download.koha-community.org/koha-3.00.04_fixed.tar.gz. I get an error message saying there's not enough disk space for the files, and this is NOT true, I have a couple of Gigabytes (and that is for sure, I have no doubt about this) and the message says I have 200 MB, 300 MB, even 0 Bytes! Every time I try decompressing it gives me a different number (a false one), and I have no idea why this happens. Could it be that the file is corrupt? I doubt it though, cause a professor gave me the link to download it so I guess he didn't have problems with it. Any ideas or suggestions? Thank you all