I believe it may be internal bios or other settings by Acer. I have a Acer desktop (horrible customer service and will never purchase any of their products) and a Asus laptop. I purchased a Microsoft office 2010 license for three computers and oddly the only one I have had this issue is the Acer desk top. Emails just disappear from the inbox only. I have check every setting with my laptop... I have had other odd issues such as I could not access ITunes store. This was not resolved until I had to wipe the hard drive and reload it. The computer came this way. I also noticed that some programs are not actually saving my last use.... but only on the Acer. Of course they want to pass it off as "software" problem.

What brand of computer are you using?

Tara