can't boot to recovery...?

[xoluvsdance12]

i'm having another problem and i was wondering if anyone could help me...backing up using sprecovery is working fine but when i try to backup using rom manager, after i click backup my phone reboots and then when i open rom manager it says recovery failure. then it gives me three options; recovery mode is broken, rom manager doesn't reboot, and other. does anyone know why this may be occurring?