Emulator

What steps will reproduce the problem?

1. Launch Sonic Hereos (GC PAL)
2. Start a game and play about 1-2 minutes

What is the expected output? What do you see instead?
Well, image should not freeze completely.
Dolphin version with the problem? Other Dolphin version without the
problem?
As far as I remember, it happened in the early 62xx series, never before.
32-bit or 64-bit and any other build parameters?
64-bit, DX9 plugin (doesn't seems to happen in OGL)
OS version and versions of tools/libraries used?
Win 7 x64, HD5850
Please provide any additional information below.
While the music still plays normaly when the graphics have freezed, it seems that the emulation doesn't work anymore because I don't hear any more "special effect" sound like when you Jump, change character, etc.
I remember that someone tried to fix a graphic freezing issue after he commited someting himself; wasn't far ago but I don't remember exactly.

When the graphics freezes, stop the emaulation and start it again, it works longer (at least I can finish the first level).