Sounds like you may have either a cheap brand switch or they have got worn out. Sadly i am too far away to take a look for you..
If you buy new switches or sockets there are really 2 major brands of decent switches, the first (and most common choice by us Pros) is called "PDL" and the other major player is "Clipsal". If your outlets are either of these two makes and fairly new then you are unlikley to have any problems unless poorly installed of course!
Cr*ppy modern day electricians, I reckon (queue Lee Bennett comment)
Urrghh?
Hey mate dont blame the tradesmen! The biggest problem with lights blowing (both here and UK) is the quality of the lamps, i used to get many calls in one town back in UK, with people saying there lamps blow each week etc etc, when i discovered they were "Tesco" lamps i laughed inside! If you want lamps that should work fine for months/years etc then i would stick to the main players ie: Phillips / Osram or Silvania. Honestly a lamp is not the same from wherever its made..
And fair point on some of sparkies i have seen here! But never fear i here to sort em out! LOL
Ian is also correct on the hater thing, 10A is the max safe load on an appliance here (there are 15a outlets too, but not usual in houses).