Building an iOS app that takes pictures, first time always crashes

[Geoff Canyon]

I'm testing on iOS 7.0.4 on a 4S, and every time I build a new version, it
crashes when trying to take a photo, until I take one with the
front-faceing camera. That succeeds, and from then on either camera will
work most of the time, but every once in a while, the back camera will die.
Any ideas? The code I'm using is below:

 on takePhoto
   if the environment is "mobile" then
      mobilePickPhoto "camera",300,300
      if the result is "cancel" then
         exit takePhoto
      end if
   else
      answer file "pick an image:"
      import paint from file it
   end if
   put the long id of the last control of this cd into imageID
   set the lockLoc of imageID to true
   toSquare 300,imageID
   set the loc of imageID to the loc of this cd
   set relayerGroupedControls to true
   set the layer of imageID to the layer of imageID
   set the alphadata of imageID to the uAlphaData of this stack
   enable control "start" of group "controls"
   set the blendlevel of control "start" of group "controls" to 0
end takePhoto

on toSquare S,imageID
   put the width of imageID into W
   put the height of imageID into H
   if W = H and W <> S then
      set the width of imageID to S
      set the height of imageID to S
      crop image id (the short id of imageID) to the rect of imageID
   else if W < H then
      put round(S * H / W) into H
      put the rect of imageID into imageRect
      put item 1 of imageRect + S  into item 3 of imageRect
      put item 2 of imageRect + H  into item 4 of imageRect
      set the rect of imageID to imageRect
      put (item 4 of imageRect + item 2 of imageRect - S) div 2 into item 2
of imageRect
      put item 2 of imageRect + S into item 4 of imageRect
      crop image id (the short id of imageID) to imageRect
   else
      put round(S * W / H) into W
      put the rect of imageID into imageRect
      put item 1 of imageRect + W into item 3 of imageRect
      put item 2 of imageRect + S  into item 4 of imageRect
      set the rect of imageID to imageRect
      put (item 3 of imageRect + item 1 of imageRect - S) div 2 into item 1
of imageRect
      put item 1 of imageRect + S into item 3 of imageRect
      crop image id (the short id of imageID) to imageRect
   end if
   set the loc of imageID to the loc of this cd
end toSquare