clutch vibration
 

I'm about to send my car for LN IMS, RMS and clutch work on my 02 boxster. I'm experiencing a brief vibration when I depress the clutch pedal shifting from 1st to 2nd gear or when just disengaging the clutch especially in 1st gear. This happens when I depress the pedal, the shifting itself is smooth. I do not feel this vibration when shifting to other gear. I can eliminate/reduce this vibration by pressing the clutch pedal really fast.

Does anybody know whats wrong with my car?

the clutch kit comes with new throw out bearing. I guess I might put new engine mount since I'm closing to 50K miles...