Thanks everyone for your guidance!
As you know, I have been looking into the difference between modified and pure sine waves; it seems that most of the problems centered around clocks!
Digging a bit deeper, it seems that it is the wave form that is the problem and not the rating. The modified wave is basically a decreasing and increasing voltage, that mimics the AC, that is produced by a decreasing and increasing square wave pattern.
A square wave is either on or off, one voltage or another, and it is this that causes the problem with clocks and other related timing circuits ie, DVD, PCs, Microwaves etc.
A pure sine wave inverter mimics the true sine wave of the AC and therefore does not have this problem.
I will be getting a pure sine wave inverter.
So now which one