I installed Mint Gloria and had the same problem I had with Ubuntu 9.04.
I did some research and discovered the problem is probably with my graphic card (ATI Radeon X800GTO). There's no linux driver for this model anymore. The open source driver does't work, so it freezes all the time.
I had to come back to Felicia, at least untill I get another graphic card.
I'm sorry I can't use the new MintMenu.