My Acer Aspire One has the same problem. Thought it was the OS, changed that, thought it was the BIOS (updated to the latest 3310 version) and still the problem is there. Now im beginning to think it might be a hardware problem and im opening up my machine tonight to see if I can fiddle around. Inn case you resolved your problem let me know how you did it
My computer tech found a solution for my Acer laptop. When the white screen comes up, simply hit the Fn (function) button, then F6 and then the Fn key once again. since he did that, it has never had a white screen again.