iCal problem

Hi,

I have had my mac for a little while now and have just started to get a problem with iCal.

When I open the application I get the following error:

"Calendar Cache" could not be moved because you do not have the appropriate access privileges for Calendars".

To view or change access privileges, select the item in Finder and choosed File > Get Info.

I have done all this but still get the same error! The settings are all set to Write and Read.

Any advice would be very welcome.

Regards
Tom Bennett