First off, I recommend checking this thread out: http://www.dreamviews.com/f79/sleep-...tified-131380/

Secondly, the issue you described is actually quite normal. Vibrations tend to appear in N2 sleep, and a normal person will experience 2 N2 phases separated by N3 sleep before slipping into REM. If you can keep your attention balanced between your anchor and consciousness, your excitement contained, and your thoughts steady through the N3 period, you should be fine.