[woodsman]

I had the same symptoms 3000 miles after having a shop install a new IMSB, LWFW, RMS and clutch. Everything was fine until I hit 4000RPM then the clutch pedal was limp (and not returned to top position) when I shifted next. In the next 2000 miles it got worse. I pulled it apart and found 2 clutch cover bolts had backed out and the release bearing had unhooked from the arm because the spring fingers were uneven since the cover's bolts were loosening. I installed a new release bearing and disc, TIGHTENED the bolts and everything's been fine since.