[Koha] Server Error: opac-main.pl, path problem

[Library]

I tried to install koha-2.0.1. After installtion, the home page 
cgi-bin/koha/opac-main.pl, in browser gave following error.

> The server encountered an internal error and was unable to complete 
> your request.  Error message: Premature end of script headers: opac-main.pl 

On manual running it gave following error:

> [root at glide cgi-bin]# ./opac-main.pl
> Can't locate C4/Auth.pm in @INC (@INC contains: 
> /usr/lib/perl5/5.8.0/i386-linux-thread-multi /usr/lib/perl5/5.8.0 
> /usr/lib/perl5/site_perl/5.8.0/i386-linux-thread-multi 
> /usr/lib/perl5/site_perl/5.8.0 /usr/lib/perl5/site_perl 
> /usr/lib/perl5/vendor_perl/5.8.0/i386-linux-thread-multi 
> /usr/lib/perl5/vendor_perl/5.8.0 /usr/lib/perl5/vendor_perl 
> /usr/lib/perl5/5.8.0/i386-linux-thread-multi /usr/lib/perl5/5.8.0 .) at 
> ./opac-main.pl line 7.
> BEGIN failed--compilation aborted at ./opac-main.pl line 7.
> [root at glide cgi-bin]#

If I include path like  perl -I /usr/local/koha/intranet/modules/ 
opac-main.pl , then it executed fine.

On using:

export PERL5LIB="/usr/local/koha/intranet/modules"

it runs fine, when used as ./opac-main.pl

and 

[root at glide cgi-bin]# export

shows following:

declare -x PERL5LIB="/usr/local/koha/intranet/modules"

But through browser, it gave same error of "Premature end of script 
headers: opac-main.pl".

What will be solution?

-- 
H.S.Rai