Maybe you heard about problems flashing 4870 cards. The problem is that the 4870's BIOS is 128 kB instead of 64 kB in file size. ATIFlash, WinFlash and GPU-Z 0.2.4 and earlier however read out the first 64 kB only. So, the file you get this way will be corrupted. Flashing such a file (modified using RBE or not) to the card will prevent the system form booting. Before flashing a 4870 BIOS (or even before loading such a file into RBE), please double check if the file has the correct size of 128 kB. If so, I wish happy modding using RBE! All 64 kB-sized 4870 BIOSes in the TPU database have been deleted. There are correct 128 kB-sized BIOSes there already if you need. For further information, see this!