Aspire 7750G cooling fan stops working; must reflash BIOS to reenable

I have an Aspire 7750G issued to me for work, and I continuously run the CPU at 100%. Unfortunately, the cooling firmware seems broken — it will stop running the fan entirely, letting the core temperatures brush up against 100°C while throttling the CPU speed down to prevent going over that temperature. Every time this happens, which is upon boot, at least every day or two, I have to reflash the BIOS (!) to fix it. (Nothing else I've tried has had any effect on this — no Windows settings, no BIOS settings, not resetting BIOS settings to defaults, nothing.)