I've noticed that if I try to freeze a track (audio or MIDI) where there are no clips near the beginning of the track, (i.e., the track may just contain a few short audio or MIDI clips in the middle or near the end of a song), Live 7 will become unresponsive at the point where the first clip begins.
In other words, if the first clip is four-fifhs of the way into the song, the software will become unresponsive when approximately 80% of the track has been frozen.
The same phenomenon will occur when attempting to Render to Disk.
The software (Live 7 Suite, boxed) is installed on a Dell Dimension 8400, P4 3.0GHz HT, 4GB DDR2, Intel chipset 925X (B-1 stepping of ICH6 controller), 750GB, SATA 7200RPM system HD (85% free space), Windows XP Home.
The workaround has been to bounce to a new track where the clip occupies the entire track. Obviously, not the best solution.
EDIT: A more preferable workaround is to extend clip(s) to beginning of track and to adjacent clips on the track to eliminate empty spaces. Still, not the best of solutions.