If that Firmware update is suitable for your system, they would have offered as an optional update through the WU, the update doesn't say anything about your particular model, so, I would still ignore it.
Where did you see the 1.51 version? If it was offered by Windows Update, you can update through WU after taking all precautions like connected to mains while updating firmware, make sure that the battery is fully charged otherwise ignore it.
Hi,
You need to update BIOS from Acer support site only, I would suggest against updating BIOS from any other source, you may damage your laptop using any updates from a third party source, so ignore the updates offered by them...
I have started to follow this method as Macrium developed a booting issue with the recovery disk, Hasleo too find it difficult to boot using Emergency disk created, so currently, I rely on System restore and keep a Installation disk in case I need to repair the system :-)