I've never used IE 6 but know of someone who had similar problems with 5.5. Others use IE 5.5 w/o problems. The person with the problem uninstalled 5.5 and went back to 5.1 and the problems are gone.
I would try unintalling it and then either reinstall it or install an older version.
Click
here for unistall instructions.
I think you mean pentium 166, not PII as PII were 300 and higher. How much ram do you have? Maybe your system is the limiting factor.
HTH