Debugging a product that won't import - What's the best way?

Hey folks,

I'm in the process of transitioning to vB4 on my test site, and one of my addons (photoplog pro, in this case) will not update. The product import just times out, regardless of if the existing product is installed, disabled, or removed completely.

In this case, the PP author hasn't posted on his own site in 4 months, so I'm not really expecting much support there. That said - as a general question and not as a paid modification question - what's the usual process for debugging a product that won't import?

It doesn't throw an error, I don't get a DB errror or email, the browser just times out. I've tried different browsers, and various states of the old plugin, but still no go.