Lion isn't set for release for a couple weeks yet. Whatever you have read is probably from a beta test and Apple has worked on it by now.
Ever since 10.3 I've read "spook stories" about everything that is supposedly "incompatible with the newset build".
Most of them are propagated by people who simply don't want to fork over the $129 for a new DVD and want to keep everyone else using what they are until they have the extra cash.
For reference, I read that here:
It's a wiki, so lots of different people will be adding their experiences with Lion developer preview builds and the current golden master release
They will probably update Reader once Lion is out to public on MAS for $29.
Also, be warned, that there's a bug in Flash Player on Lion. (If you try to change any settings by right clicking, while setting popup appears, you can't click anything)
However, how Apple released Final Cut Pro X without warning, I have feeling Lion may be released without warning, which might give devs like me a huge headache. (I am Mac Developer, but I'm also a freelance graphic designer web developer, and I depenend on Flash/Dreamweaver for most of my HTML5 projects, and Dreamweaver's been buggy somewhat in Lion)
What version of Dreamweaver are you using? CS5.1 from CS5.5 or the DW from CS5.0 or some even older version?