Gutted it's Acer, sometimes you will get pretty good service, other times you will get shoddy service (I puchased an Acer Advantage Pro warranty for my old Acer laptop, which included "priority support and repairs" and a 5 day pick-up and return guarantee, and once they decided to replace my DVDR drive when I sent it in for a HDD failiure, and they took 3 months to source the DVDR, well thats what they said - not to mention them using refurbished HDD's for replacement, that kept failing within days of getting it back, in the end I just bought my own!).
Get on the blower to Acer and see what they say; the likelyhood is they will need to repair it, simply because the problem is likely to get worse over time, and it certainly does sound like a hardware fault.
Though unlikely (but hopefully), it could be a BIOS or driver problem that has been resolved in a newer release - have you checked the Acer support site?
Acer UK SupportAcer UK Download Area - check that your BIOS and display drivers in particular, are up to date.
Acer UK Online Repair Booking Service - You will have to wait until Monday most likely for a reply, but it will be cheaper and less time-consuming than phoning them (they tend to have 1 hour queues from the minute their switchboards are turned on, in my experience).