Display dialog ... giving after integer

Question

After updating to Mountain Lion I experienced some problems with the AppleScript scripts I use in a Filemaker Pro environment.
This necessitated me to change from QTP to QTP 7.
The following script reflects the FMP environment; when I try to abstract from the FMP environment, I encounter other problems.
tell application "QuickTime Player 7" to launch
tell application "FileMaker Pro"
  activate
          set url_path to cell "bestandspad" of current record
end tell
set tekst to ""
tell application "QuickTime Player 7" to getURL url_path
delay 0.1
tell application "System Events"
          set visible of process "QuickTime Player 7" to false
          repeat until visible of process "QuickTime Player 7" is false
          end repeat
end tell
tell application "QuickTime Player 7" to set doc1Exists to (exists document 1)
if not doc1Exists then
          set tekst to "next"
else
          tell application "QuickTime Player 7" to play document 1
end if
set the clipboard to tekst
set tekst to ""
repeat
          display dialog "Interrupt" buttons {"Stop", "Pauze"} giving up after (my secLeft())
          set {b, fin} to {button returned, gave up} of result
          if fin then exit repeat
          if b = "Stop" then
                    set tekst to "Stop"
                    exit repeat
          else
                    tell application "QuickTime Player 7" to pause document 1
                    display dialog "Verder gaan ?" with title "" buttons {"Stop", "Hervat"} default button 2
                    set b to button returned of result
                    if b = "Hervat" then
                              tell application "QuickTime Player 7"
                                        tell document 1
                                                  if duration = current time then exit repeat
                                                  play
                                        end tell
                              end tell
                    else
                              set tekst to "Stop"
                              exit repeat
                    end if
          end if
end repeat
set the clipboard to tekst
on secLeft()
          tell application "QuickTime Player 7"
                    tell document 1
                              set d to (duration - current time)
                    end tell
          end tell
          set d to round d rounding up
          if d < 1 then set d to 1
          return d
end secLeft
tell application "QuickTime Player 7" to close document 1 saving no
tell application "QuickTime Player 7" to quit
Everything works fine, but.
The problem is with the 'display dialog ... giving up after (my secLeft())'
This is supposed to return fin=true when current time equals duration or when my secLeft=0; it always returns fin=false
This program runs fine on the AppleScript editor; 'current time' sometimes poses a problem in other programs.
Any idea how to correct 'dispaly dialog (without moving back to QTP)?

Answer 1

To induce you to a response I submit the program in a simplified form, so that you can run it in the AppleScript editor after copying; you only have to fill in the url_path.
tell application "QuickTime Player 7" to launch
set url_path to "/Users/your name/Desktop/song title.mp3"
set tekst to ""
tell application "QuickTime Player 7" to open url_path
tell application "QuickTime Player 7" to set doc1Exists to (exists document 1)
if not doc1Exists then
          set tekst to "next"
else
          tell application "QuickTime Player 7" to play document 1
end if
set the clipboard to tekst
set tekst to ""
repeat
          display dialog "Interrupt" buttons {"Stop", "Pause"} giving up after my secLeft()
          set {b, fin} to {button returned, gave up} of result
          if fin then exit repeat
          if b = "Stop" then
                         set tekst to "Stop"
                         exit repeat
          else
                         tell application "QuickTime Player 7" to pause document 1
                         display dialog "Continue ?" with title "" buttons {"Stop", "Resume"} default button 2
                         set b to button returned of result
                         if b = "Resume" then
                                             tell application "QuickTime Player 7"
                                                       tell document 1
                                                                 if duration = current time then exit repeat
                                                                      play
                                                       end tell
                                            end tell
                         else
                                        set tekst to "Stop"
                                         exit repeat
                         end if
end if
end repeat
set the clipboard to tekst
on secLeft()
          tell application "QuickTime Player 7"
                    tell document 1
                              set d to (duration - current time)
                    end tell
          end tell
          set d to round d rounding up
          --if d < 1 then set d to 1
          return d
end secLeft
tell application "QuickTime Player 7" to close document 1 saving no
tell application "QuickTime Player 7" to quit
It seems, that 'repeat' is not working. The value of secLeft() is not refreshed while playing.
I tried repeat while and repeat until, but to no avail.
Comment please.