the sims petz gba is acting up

i downloaded both versions of the sims pets for gba ( by lightforce and rising sun) but when i run them on my visual boy gba emulator, the game starts to flicker and the images get distorted. so is this a problem with the roms of my emulaotr?
please help thanks.

emulator most likely. Make sure you are using the latest version

Emulator yes, use this one:http://vba.ngemu.com/downloads/VisualBoyAdvance-1.8.0-beta3.zip

hey it works. thaks very much guys... :D