"Error #400-Bad Request" when launching Elements 2.0

When I lauch Photoshop Elements 2.0 (Mac with OS 10.2.8), I recieve a message that says "error downloading from Adobe Online web server ... The request was not undersstood by the server. HTTP #400-Bad Request." In the bottom left corner of the error window it also says "18:400" Sometimes I am able to click "OK" and continue without any problem; other times the application hangs after clicking "OK"

Can anyone identify the problem and tell me how to correct it?

There are many reports of various kinds of errors at launch that somehow connect to the Adobe Online services. Most of us go to Edit>Preferences>Adobe Online and turn the 'check for update' frequency to Never. Interestingly, most people have no trouble accessing updates (although there are none!) manually. For some reason that automatic feature causes more trouble than it's worth.