My little LazyWeb mewl from a few weeks ago didn’t really generate much in the way of attention, though one poster, Matan Ninio, was apparently able to get things working with a manually specified proxy:
The problem seem to be that iCal does not know how to work with a proxy.pac file, but does know how to work via a proxy. Just enter the proxy address and port directly, and suddenly all is well again. (at least thats the case with our 10.5.2 machines)
Better by far you should forget and smile than that you should remember
and be sad.
— Christina Rossetti