When I open iCal I noticed all of events are double events I don't know how to explain but I hope you know what I mean? Anyway how do I prevent of having double events in same day?
Start by checking if the duplicate events belong to the same calendar. If not, then you can delete one of the calendars. I've had this happen in the past with MobileMe, where a calendar was duplicated and I ended up with one local version and one MobileMe version.
How many Macs and iDevices are in your sync loop? Also, make sure that you don't set up sync in two places simultaneously, that iCal sync is disabled in iTunes if you use MobileMe or iCloud.
duplicate events is what I meant thank you, doc69...anyway right now I have one mbp and one iphone. also I have itunes running on 2 windows pc and one mbp if you must know...so tell me how...
I have seen other people getting duplicate entries when they included PCs in their sync chain.
Are you using iCloud to sync all devices? If so, have you disables iCal syncing in iTunes?
Does your duplicate entries belong to the same calendar or to two different ones? Right-click an event on your Mac and choose "Calendar" in the drop down menu to see which calendar the event belongs to.
I use MobileMe, not iCloud, so I'm not sure how it will look like in iCal. But your events should probably be either "This Mac" or iCloud. It looks like you have a duplicate local copy of your events on your Mac as well as the iCloud events.
No problems with function (for me), but man that is one ugly faux-paper calendar. iCal was no beauty queen before, but at least it wasn't distractingly ugly.