allsorts,
I now have 2x2GB - when I upgraded I thought that was the max, so I may just go for 2x4GB. I am thinking of getting an iPad to replace my aging laptop, so I will have a look at ScreenSharing.
It does seem that A+ MAY be more affected by environment than PM - which is odd because a lot of comments about PM refer to 'glitchy' behaviour which is not what I have found!