Problems with Modification Date of folders on server

I have an app that should pick the folder with the oldest modification date, and moves it to a specified place. My problem is, when I test just this bit of code, it works OK every time on my computer. When my app actually runs on a different computer, this part to pick the oldest folder does not work… UNLESS I have the window of the source opened and I have changed the display to List and sort by Mod Date in the Finder. Then it works OK. If I do not have the Finder window sorted first, it just picks either random folders or the folder with the last name alphabetically. Am I doing something wrong, is this a bug, … ?

tell application "Finder"
				--LETS PICK THE OLDEST MOD DATE FOLDER, SO FIRST IN FIRST OUT
				set sortedFiles to every item of folder myWatchedFolder
				set sortedFiles to (sort sortedFiles by modification date)
				move last item of sortedFiles to myWorkingFolder
--or use get last item of sortedFiles --just to test
end tell
				

OS X 10.4.11, XCode v2.5
Servers Windows mounted via AFP

This is a different approach that doesn’t actually sort the list it should just find the oldest item by using a comparison. Might help might not but here it is anyway. I didn’t actually put the move file bit in, I just had it open the folder or file for testing.

set theOldestdate to (current date)
tell application "Finder"
	--LETS PICK THE OLDEST MOD DATE FOLDER, SO FIRST IN FIRST OUT
	set theFiles to every item of folder myWatchedFolder
	repeat with afile in theFiles
		set thedate to modification date of afile
		if thedate < theOldestdate then
			set theoldestFile to afile
			set theOldestdate to thedate
		end if
	end repeat
	open theoldestFile
end tell