I haven't seen it mentioned anywhere, but checking the game's update log purely for shits and giggles, I saw this:
Warhammer 40,000: Dawn of War II
- Improved memory heap management to reduce 'out-of-memory' crashes that were plaguing certain systems, including 32-Bit Vista on High and Ultra settings. Often reported as 'error 183 failed to create to create dump'
Overjoyed.
(CW)TB
