[Tails-dev] bug report

Black screen apperar after boot menu before tails the greeter
1.i want to start the latest version 1.1.2
2.i start from usb and from dvd without succes
3.the previous version 1.1 work fine
4.i have try on other computer with the same result
5.i have try debug option and no error appear ,the same black screen appear
6.I have try and 1.1.2 rc and the same black scren
7.Previous version of tails work perfectly