In certain dialogues in WeBuilder 2006 and 2007, using Select All fails and simply does nothing. A quick example is the hyperlink creation boxes, where you type the URL and whatnot in; however, it affects most throughout the program.
Related to this issue but possibly completely different to fix is using Select All in the search or search/replace dialogues. When you do it in here, which would be particularly useful in search/replace to copy what's in the first box into the second box, the focus remains on the document and the whole text of the document is selected instead of what's in the dialogue box you're focused on.
I'd personally consider these bugs as general Windows functionality dictates that if a dialogue field is focused on, Select All takes effect in that box and not whatever else might be open.