Question about clutch

[sasha055]

Hi,
I had a squeal from the back of the car every time I would start moving (release the clutch). Squeal would appear only after car was parked for more than 2 days and would go away after a warming up, it turned out to be new belt that I put in 1 year ago.. however I was so sure it was clutch that I started paying a lot of attention to it.. and now I think something is wrong with the clutch

When releasing the clutch it seems that its a two stage release, it catches first very close to the floor then very high, with pedal almost de-pressed.
IF I rev the engine it's smooth, however when starting at 1500 RPMs is feels like the clutch catches, car starts moving, then almost chokes, then it catches again

Is it normal? Do we have a 2 stage clutch?

Funny how before I never noticed it and was driving fine.. now it drives me crazy!

I have a 2000 Base Boxster with 80K miles on it

Thanks
Sasha