Site Import has never worked for me

I have tried everything working with tech support to get this extension to work and actually import a full site. It has never done this for me. I get maybe 3-4 files imported if I'm lucky. I've had a support incident open now for 2 months, I've even since installed DW CS4 (after uninstalling DW8) for other reasons and despite 2 different DW versions and not upgrading from one but completely deleting it and installing the full CS4 version still get similar error messages like the following:

TypeError: allUnknownMatch has no properties
TypeError: matchArray has no properties
TypeError: allUnknownMatch has no properties
TypeError: extensionArray has no properties

I am clearly frustrated with products like this that have not functioned properly from the outset and no one can correct it for me. I just keep getting asked to delete my configuration file and re-install all of my extensions like I have all kinds of time on my hands to do this yet again. I am so unhappy that WA puts out products like this that clearly do not function as advertised and worse that no meaningful solution has been offered. Is there any hope??