I know nothing about Apache::AuthenNTLM, but I assume you did the obvious things, like restarting Apache etc?

One reason might be that you have written your handler as a method handler (sub handler ($$)), but are calling it like a normal handler.

Try this in your httpd.conf

PerlAuthenHandler MyOverride->handler
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Or change your handler to a "normal" handler, like so:

sub handler { 
    my $r = shift;
    ...
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What about not printing to STDERR, but to use $r->log->error('bla')

You could post you message to the mod_perl mailing list, but please read this before you do. There are a lot of very clever minds there...

--
#!/usr/bin/perl
for(ref bless[],just'another'perl'hacker){s-:+-$"-g&&print$_.$/}
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