Def: does this lock-up happen every time there's an explosion, or only if you have your camera aimed at it (i.e. observing it)? My suspicions fall on the beta drivers you're using. Try an older version and see if it happens again.
ETA: Just a heads-up, if you're planning to use the latest TM and ROW Sounds on top: you'll need a small fix to use those two mods together. I released it a while ago, but I'll be damned if I remember even the name of the mod! :rotfl: Let me undig it for ya!
ETA#2: Found it! Go grab it
here. Disregard the "For TM SP2" part, it's still a viable fix. Install it AFTER TM and ROW Sounds.