Micromax Funbook tablet frozen at boot screen. No clockwork mod recovery - how to restore?
This link helped me to flash a rom image. As an additional benefit, this ROM seems to be faster than Micromax's original ROM and also claims to support a list of 3G dongles.  The previous (i.e. original) ROM I had did not support Reliance and BSNL's 3G dongles.

As in a settings menu the following dongles are supported (I haven't got any 3G dongle to test):

WCDMA:
Huawei(E230, E176G, E160E, 182G, E1782, E1750 UMG1691), ZTE (MF633BP-1, MF633, MF637U)

CDMA2000/EVDO:
Huawei(E150, EC1261, EC122, EC156, EC1270), ZTE (AC580, AC2736, AC2746)

After re flashing, I installed clockworkmod recovery as per this link as well.