Hello every body, i just bought a 3250, and amazed by the phone, but i'm tryin out all my 6600 apps and they just don work...

Only Java (.jar) programs for the 6600 will work. For "native" Symbian/S60 apps (.sis), you need new versions specifically for S60 3rd Edition because there have been changes that requires that (low-level stuff; new compiler, new processor instruction set, new security things in the operating system).