Here is a very good reference on IE CSS bugs:
If you want to have a better understanding of why sometimes IE behaves strangely, take a look at
You may also want to check out
This site is not strictly about IE CSS bugs, but contains a lot of very useful information about browser issues.
If you still have troubles with IE6, you can provide more specific information about your scenario (live URLs will be quite useful) and I will try to give further advice.
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