Regarding your first issue, what desktop environment are you using? I have found in the past (running Fedora Core 2/Crossover 3.0.0) that when in Gnome Dreamweaver would exhibit odd keyboard behaviour as you describe - cursor keys don't work, backspace is the equivalent of 'undo' etc. I had no such issues under KDE though - if you have access to both you may want to try and see if that solves your issues. Might be something to do with the way Gnome handles keyboard events...
Can you tell us what javascript errors you get on these menus, and if you get them anywhere else? Are they consistently reproducible? Some more details on your system might throw something up as well... Otherwise, check the errors for the path they refer to - I've had issues with other apps that use inconsistent capitalisation - of course, not an issue under Windows, but is in Linux. If it looks like there are inconsistencies, you may want to create a link to the offending directory with the required caps. For example, if there are two pieces of code referring to 'Header/header.js' and 'header/header.js' (don't know if there is - just a random example), then execute;
ln -s Header header
(Assuming 'Header' exists already and 'header' doesn't).
Hope that makes sense, and can be of some use!
Cheers,
Peter