Please report your test results to the author of the module. You can find the author's contact address on CPAN at http://search.cpan.org/search?dist=Net-Telnet
. Also, you may want to send the same to the CPAN-Testers mailing list. The module's page shows that the tests fail for two platforms, but pass for 14. Are you using i386-linux?
If you change the tests so that they do not fail, are you soving a problem or creating one? If the source of the failure is in the module, then you are very likely creating bigger problems for yourself later on.
The goal is not to have the tests pass, but to have the module work as it should.
If you report your results to the author, you'll take a step towards helping others avoid the same problem, and towards helping the author improve his module.
More at http://testers.cpan.org/ and http://mrbbking.perlmonk.org/