Hi, John! I think quite a few of us Sony Reader owners wish Sony would allow for purchases across the web, rather than through the Sony software. I know it runs slow on my system, but I'll admit that didn't happen until I upgraded by Internet Security software. (I have problems installing Calibre with my Zone Alarm enabled, too!)
But if something made you decide the 700 was your "Reader of choice" in the first place, I'd suggest trying Jon's suggestions before you give up on it.
And this is probably a dumb question, but do you know for sure if you have the right version of the software - it should be 2.5.00.09170 (per the Sony support website).