I believe this crash/desync is related to a timing bug in the sound sub-system. If a process takes way longer than expected to process it can cause the game to get out of sync and/or crash since there are no checks past that point in time to see if the sound event has completed or not. It might also occur if a process takes way less time than expected. (I'm a real-time software engineer, so these are educated guesses on my part. I've never done any actual game programming, however).
From the reports I've seen, it does appear to be related to "announcements", with the map-control event being the worst one, since the CPU is typically very busy at this point in the game handling 100s of creeps.
This crash/desync is hardware specific since it depends on the efficiency of your PCs sound system. So, on your machine, you are likely to see a crash/desync every time the map-control announcement is issued. But, that doesn't mean it happens for everybody. It only happens to me in 1 out of 10 games. So, to ask every body to avoid map control in every game is overreacting. A better approach would be to inform people at the start of the game that you will crash on the map control announcement, so the other players can avoid it in games that you are playing in.
You could try making your sound system more efficient (or play with no sound) and see if that fixes the problem. See the sound problems threads for ideas.
Of course, the better solution is for GPG to fix the bug, but these types of bugs can be very hard to fix, since they are hardware dependent and almost impossible to reproduce without having the exact combination of hardware where the bug occurs.
