Nice sniffing it out what would change that.
Then I can help you with a workaround so you won't have to edit every file.
First, you need to locate this file (here is the path on Mac... not sure what OS you are using):
Once you get to iRiteShared.js, open it and go to line 1188.
It will read:
this.SkinPathReplaceText = "FCKConfig.SkinPath = '@@ValueToken@@';";
Now, change it to this:
this.SkinPathReplaceText = "FCKConfig.SkinPath = FCKConfig.BasePath + '@@ValueToken@@';";
Then save... close and reopen Dreamweaver if it was previously open. Then BAM (as Emeril would say)... you now have your nice dialogue boxes all the time with no more additional editing.
I reckon WebAssist could use this fix for a dot release as well.