Problem importing from Yahoo Calendar into Google Calendar

I have been using Google Calendar to keep my schedules synced between my hand phone and the online calendar. However I want to import all my birthday and anniversary reminders from Yahoo! calendar. Now this seems to be causing a lot of problem. I keep getting a silly error:

Processed zero events.

Failed to import events: Unable to process your iCal/CSV file. The file is not properly formatted..

Has anyone got a similar error. I tried doing a google on it but there wasn’t anything very helpful. Let me know if you guys have been able to tackle this issue.