I just tried out the portable sunbird, great program except for this flaw. When I import iCal from Calendar.Google.com the repeating tasks repeat every day, regardless of the fact that they're setup for weekly events... and not only that it appears to wrap around the year in an infinite loop.
When I look at the "end" date, it shows December 31, 1969.
I downloaded the latest official version just now and the exact same steps work flawlessly. I'm thinking its just a lil bug somewhere.
Also my events have no end time, but even when I added one it didn't seem to make a difference, it just kept on repeating them.