Why does my G3 B/W (OS 9.2.1) slow down after sleep mode?

King Tut wrote on :

Ever since I installed MacOS 9.2.1 on my B/W G3 it behaves as if it was moving through molasses. The typing lags way behind (and I am no fast typist). I have had to stop putting it in sleep mode at all to avoid this.

I would really like to know why this happens. I had no such problem with 9.1