Thanks to the anonymous monk for his work. Unfortunately, I get cargear=1 too.

WWW::Mechanize 1.60
LWP            5.831
HTML::Form     5.829
[download]

At the moment, the only conclusion we can draw is still "there's a bug in the code the you didn't show us". Still waiting for a minimal, runnable snippet that demonstrates the problem. We can't help you if you don't give us the info we need to help you!