how to adjust @INC Path of Perl

["Thomas Gebhardt" <gebhardt@HRZ.Uni-Marburg.DE>]

Hi,

on my slink system perl frequently does not find its modules.
I get error messages like this:

Can't locate Net/FTP.pm in @INC (@INC contains: /usr/lib/perl5/i386-linux/5.005
 /usr/lib/perl5/5.005 /usr/local/lib/site_perl/i386-linux 
/usr/local/lib/site_perl .) at /usr/lib/dpkg//methods/ftp/setup line 7.
BEGIN failed--compilation aborted at /usr/lib/dpkg//methods/ftp/setup line 7. 

It seems that the missing modules are somewhere else:

/usr/lib/perl5/Dpkg/Archive/FTP.pm
/usr/lib/perl5/Net/FTP.pm

How can I correct the @INC Path variable? Any hints what might
have damaged the previous configuration?

Thanks, Thomas