[NTG-context] slower access to ConTeXt generated pdfs in Windows Vista

When opening ConTeXt generated pdf's in Windows Vista, a message window pops up saying something as (translated to english): - title: preparation of document contents" - message: "please wait while the contents of your document is being prepared" + progress bar "page x of total pages" This doesn't show up in Windows XP or Linux. The embedded fonts are ttf fonts like arial/tahoma/verdana/times new roman, ... Any idea to what that's related and how to disable it/have it run in the background (if possible) because it slows access to reading the pdf. -- Alan