Mobile Me Nightmare

I am experiencing a nightmare with the new Mobile Me iCal upgrade! First all my calendar data disappears off my iMac and now mobile me wants to delete 2,000 items from my laptop. Finally I get a new calendar set up using instructions that would daunt a microsoft user. Now iCal doesn't recognize any of my contacts for invitations so I have to manually enter them. Does anyone know how to correct this? It worked just fine before. And also does anyone know how to make iCal send the invitation from my work email address, it now will only send from my personal mobile me email. It is a nightmare. Come on Apple.