TWD mini-freezes issue

[GrenouilleToxique]

Hello,

I've got some freeze issues with the PC (Steam) version.

The game is usually smooth (85fps i suppose), but time to time i got screen freeze for fragments of sec.
It happens in dialogs, when camera suddenly changes plan, etc.
The worst case i've encountered until now is at the very beginning, when lots of zombies come in the forest. In this scene I can only hear Lee falling multiple times but i never saw the animation due to freezes...
The game is still playable, but it really break immersion !

It's worth noting that i finished BTTF episode 1 (telltalegame's version, not steam's one) and didn't get that kind of problem.

When mini-freezes happens cpu usage goes up to 80%, with core1 at >90% and there's usually read-access on "4_WalkingDead101_english_pc_ms.ttarch" file (cpu working on media decompression/decryption ? or maybe scripts compilation/interpretation ?)

For the "zombies come from forest" scene (the worst case i encountered for now) there is a lot of "NO SUCH FILE" errors which could explain why this scene freezes even more than others (see attachment for filemon's log).

My config :
CPU : Intel dual core E5200 @2.9Ghz
GPU : Ati radeon 5700
HDD : Western Digital Sata 1TB @ 7200rpm (where game is stored), and Samsung Sata 1TB 7200rpm (for system/userprofile/swap/etc)
RAM : 4GB (caped to 3.25GB)
OS : Windows XP sp3 32bit

edit : game's files are defragmented

[GrenouilleToxique]

After looking another topic (i didn't saw it first because i've searched "freeze"), it seems like lowering shadows settings to off or low make things much more smooth.

So it doesn't look to be cpu/hdd related as i thought...