No recovery

[Guest domenico lamberti]

a few days ago i installed a customs ROM , a version of pauls alpha R4 rom that i made myself , but today i tried to flash the Alpha 5 ROM i had recently cooked and found that i could no longer get into recovery mode, it stays on the green android and has the red LED behind the back button and when i go into ROM Manager and try to insal the ROM that way it tries to boot into recovery then fails , the only way out is a battery pull , how have i done this and how can it be reversed ?