Based on the very limited info you've provided - its a bit hard to provide much help.

Maybe consider:
1. Paste your code thats 'exiting'
2. Provide the specific output thats being generated, or specificy at what point your code is exiting.

At a guess, it might be due to an exception thats being thrown in one of the modules that www::mechanize uses. If so, you can neutralise it via a block eval.