Have Míicrosoft problems with XBox 360?

By some internet phorums, people who bought Microsoft new console XBox 360 have prolems with its stability, machines are during game freezing. Microsoft oficially announced, that those problems have only very little number of xboxes, but at newt, there are pretty much people saying they have problems. If that is true, it can help Sony with introducing their new console, which is of course last thing Microsoft want.