It seems there are problems with opening Help pages depending if opens via F1 or Help button. I tried Insert menu items in Writer. This is not content focused but opening issue, so marked Writer. Tested with current Win 6.2+. Help button for Signature (after Bug 118115) opens help but general Writer help instead of Signature help. F1 works, help exists. This is not only Insert-Signature issue but also Insert-Envelope, Insert Footnote/Endnote, Insert-manual break. Some may have opposite problem, that Help button opens correct help but F1 doesn't. Can't say now if there's such. Some open general Writer help both for button and F1: Insert-ToC, Insert-Caption, Insert-Special Char, Insert-Bookmark, Insert-Section, Insert-OLE, Insert-Fontwork. Some open correct help page both ways: Insert-Cross-ref, Insert-More fields, Insert-Index, Biblio, Insert-Hyperlink.
*** This bug has been marked as a duplicate of bug 115254 ***