I hadn't done this myself in quite a while and I know it used to work. I just went into my logbook and clicked on the options tab. I clicked the Request button which gets grayed out and the text indicates it has been queued. I had to refresh the page since I don't think it is updated dynamically, and in less than 10 mins I had the info showing the size available and the Download button was enabled. I clicked Download and a page shows with the link to the ADI file I can save to my local computer. As a point of reference, I have 31719 QSOs in the QRZ logbook.
David - K2DSL
K2DSL Blog - http://k2dsl.com
Ham Radio Utilities - http://levinecentral.com/ham