GMod Steam Achivements Locking themselves

[Kouen]

Has anyone else encountered this?

While most of the time im not an Achievement whore, I Booted up GMod today to have some lulz and it started saying "Achievement Unlocked: Played Single Player" Which confused me but thought nothing of it as I played it kept unlocking achievements ive done months ago.

When I Looked on my steam page sure enough it relocked all my achievements except the ones I now re-unlocked, But some refuse to unlock again like "Play a mode other than Sandbox" I Loaded a Half Life 2 level (Ravenholme Hell Yea!) and That Achievement wouldn't Unlock so I tried to eat a Ball for an Achievement and that wouldn't kick in ether...

Anyone have this happen or a solution maybe?

Edit: Noticed none of the Half Life 2 Weapons are in my Menu ether :S

 

[Kouen]

Before this gets buried,

I've Tried Verifying the app cache and that came out OK.
I've Tried Deleting all local content then going into my steam apps and deleting the remains.

I'm now Deleting all my Valve games that work with GMod Deleting the remains then re-downloading them all (this includes GMod itself again)

Any help or thoughts appreciated and thanks in advance