What steps will reproduce the problem?
1. Rename Set 1
2. Rename dialog comes up
3. type in new name
4. Click "Yes" button
5. Error occurs (see below)

NOTE: error does not come if you press "Return" on keyboard instead of clicking the "Yes" button.

What is the expected output? What do you see instead?
No error.

What version of the product are you using?
latest, v3.1.0

Do you have an error log of what happened?
Date: 2009-06-29 12:43:15
ID: 1
Error occured in: Global
Count: 1
Message: ..\AddOns\ACP\ACP.lua line 443:
   attempt to index a nil value
Debug:
   (tail call): ?
   [C]: ?
   ACP\ACP.lua:443 OnAccept()
   ..\FrameXML\StaticPopup.lua:3057 StaticPopup_OnClick()
   [string "*:OnClick"]:1:
      [string "*:OnClick"]:1
AddOns:
  Swatter, v3.1.13 (<%codename%>)
  ACP, v3.1.0.17
  (ck=bc2)

Please provide any additional information below.