Today I attempted to install a ROM for the first time using ROM Manager. I flashed Clockwork Mod Recovery and then downloaded CyanogenMod and tried to install it (pressed Reboot / Install in ROM Manager). My phone then went into Download/Odin mode. It then didn't do anything for ~10 minutes, and after taking out the battery, the phone still went into Download mode. I got it to boot normally by pressing Home + Power + Volume Down and then pressing cancel when it prompted me to enter download mode. However, every time I attempt to boot into recovery, normally or ClockWork, the phone just goes to download mode. I even tried to do a factory reset, and the phone booted again into Download Mode.
Does anyone know how I can fix this?