strange problem Beach Spikers/Mario Kart Wii

[danuota]

Hi guys .
(ehm sorry my english , use a translator...)

I'm using this magnificent emulator with some titles Gamecube / WII , okay , running fluids for both video and audio , but I have a strange problem with both Beach Spikers (GC) (USA version ) and with Mario Kart Wii (EUR version ) :
- Beach Spikers fine , fluid , in the first meeting ( quarter-finals ) and in the second meeting ( the semifinals ) then the problems start from the end , eye-catching video and audio delays and become unplayable .
- Mario Kart Wii , everything ok with the first path , then the problems begin , especially with annoying audio glitches .

is this normal ?

use :
Dolphin 4.0.7398 fullscreen 1920x1080 , Force 16 : 9 , internal resolution 3xnative , the rest of default options

My PC :
Intel I7 4770 3.4 GHz , 16 GB RAM Corsair DDR3 , AMD 270x 2GB R9 , WIN 7 64bit

Thanks!