mhypolite,
Not sure about that. We use AR 6.0, I haven't seen 7.0, but 6.0 isn't able to view My Network Places paths, and certainly not http:// or https:// paths as the Office applications can.
One thing you might try is using your Web Client Service, map a drive to a document library by UNC path, \\myportal\sites\sitename\dlname
then try opening the Word docs from that mapped path, then saving there as PDF's. You're Web Client Service (XP, 2003 machine only), is then performing a layer of translation (http path to local path) for Acrobat, and that should work fine.
Office 2007 will include Save as PDF in the core applications, but I'd like to test automating entire document libraries saved to PDF's, but haven't had time to fool with that.