perl unzip error

[Fusun Inanc]

Hello all,

I have installed ns in my unix computer. And I also 
want to install perl. I downloaded latest.tar.gz from ns webpage.
When I try to unzip the file it gives the following error.
should I unzip it with another unzip program or I think the file is corrupted.


% gunzip latest.tar.gz
 incomplete distance tree

gunzip: latest.tar.gz: invalid compressed data--format violated
% 


Please help me on this.

Thanks

Fusun