Hey Barmy, a little advice
The Computer will not take bowlers off if they keep picking up wickets as well as being very economical. So if your struggling against the real quicks, see them off and they will be replaced. They are far more dangerous in the first 20 overs or so.
Also, when playing the quickies with the 40 mph pace variation, As you have been block out, but anything quite wide, play early and attack it, if you play and miss cos its a slower ball, no biggie, but if its a quick one you'll hammer it if timed well.
If it's straight and quick, get that block in, if your not picking the speed well you can play a block shot quicker and later than a drive (obviously :P ) so you get a split second longer to watch the ball if your blocking, but still need to play early. The key is then being able to immediately not delay the button push when the ball is flying towards you.... Or if your gonna press early, try to play down the right line and you'll at least get bat in the way.
Hmm bit of a rant there :P