small memory corruption after "safe sleep"

Following the introduction of whole disk FileVault in OS 10.7, and its local activation, a small memory corruption occurs systematically after a "safe sleep" procedure. The problem did not occur in OS 10.6, where FileVault was limited to the Users. The memory corruption is visible on screen: the windows show corrupted images, similar to old-time analogue TV when out of service, and the Terminal shows the same type of image interleaved with scrolling text. The problem does not seem to require an urgent solution, as the OS keeps functioning, and it goes away after reboot. It is annoying, however, and would very much like to see the solution with the next os update.