I first installed ClockworkMod directly, using image directory as explained here. As a result, the normal OS will not boot and the phone would always go into recovery mode.
Then I tried to restore the original ROM, which I flashed using the recovery mode. It completed successfully, however upon restart the phone doesn't go into OS again, but rather starts in some broken recovery mode. It is blue, rather than orange, and doesn't allow me to select any menu entries (but it does allow me to change them).
I can go into FMT mode by pressing VolDown during start-up. However it doesn't look like adb is detecting my phone. Windows 7 32bit sees my phone as "ZTE Handset Diagnostic Interface(DFU) (COM3)", but adb doesn't see the device at all (adb devices).
Looks like I need a way to start my phone in "fastboot" mode, as described here, where the guy has a similar problem. I tried a few key combinations during start-up, Menu+VolDown, Menu+VolUp, Home+VolUp/Down, but so far I either get the FTM or the broken blue recovery.
Let me know if you have any ideas.