No, I don't notice this. I use DW8 at work and have IE7 installed. No problems.
I do notice that DW8 sucks, and MacroDobe is on the threshold of handing away thieir lock on the majority of the semi-pro dev market. I say this having used DW since v3.
I suspect it's going to be all VS.NET for me within just 6 months.
-KF