Hang at uncompressing linux

My beagle board is hanging at "Uncompressing Linux". Sometimes it also
errors on the reading u-boot.bin from mmc screen. I think the problem
is regarding how the MMC card is seated or maybe a broken connection.

I'm trying with two cards - an Angstrom image I put together and the
RevC restore image built from the validation page. They have both
worked previously.

Any suggestions?