Optio S40 problems(?)

I just sold my Optio S4 to my brother to buy a Optio S40 because I wanted a
camera that could use AA batteries. The camera is well made and featured
and can do everything that the S4 can and then some (despite being cheaper),
but there are two things I find a bit disappointing:

1) The flash takes a few seconds to charge after it has been used and during
this time the screen is black and the camera inoperable. Why should this
be? The S4 does not do this. The S4's flash recharges instantly despite
only using a 710mAh battery and yet I am using 1800mAh NiMH batteries in the
S40.

2) The sound recorded for voice memos or movies on my S40 is much quieter
than on the S4 so that when I play back on my TV I have to turn the volume
right up which also increases hiss (turning up the playback volume on the
S40 causes distortion). And, if this is not bad enough, there are terribly
loud "pops" every time the sound clip starts and finishes.

Are these problems normal? Any Optio owners care to comment?