Hi. I put a ipod touch firmware 2.1 on my ipod toch and then jailbroke it. it was working just fine. then I wanted to install some game on my ipod touch. so fallowed an instruction on a website which said "replace Mobileinstallation with the F***ed one" and so I did. then I restarted my ipod and then nothing happend. it didnt started up. it just showed apple logo and nothing else happened. just sometimes it goes black and then again shows apple logo. and it was like that until the battery finished. please someone tell me what should I do?