0xe8008001 error

[_M_]

Hi, I recently unlocked my iphon 2g 3.0, but I didn't put cydia on it ( I felt that it slowed the phone down). When I want to sync my apps, I get the 0xe8008001 error, so is there a way to sync the apps although I don't have cydia to download "AppSync for OS3.0"? Seconed, can I still buy apps from the app store on my iphone and not get that error??