WoWInterface - Dragging frames

When I try to anchor the Quest Watch to a new frame (example: frame1) OnLoad, it dos not work right.
But if I do it On Click it works:

Quote:

function frame1_OnLoad
QuestWatchFrame:ClearAllPoints()
QuestWatchFrame:SetPoint("BOTTOMLEFT", "frame1", "BOTTOMLEFT", 5, 8)
end

function button1_OnClick
QuestWatchFrame:ClearAllPoints()
QuestWatchFrame:SetPoint("TOPLEFT", "frame1", "TOPLEFT", 5, 8)
end

Why it does not work?