Transmit 3 "on open" vs "choose file" problem

I have an AppleScript that will take the output of a Compressor droplet and attempt to upload it to a server using Transmit 3.

If I use “choose file” to select the file, it works with no problems.

If I use “on open”, like I’ll need to with the Compressor output, it fails (AppleEvent handler failed) in attempting to upload the file. There’s no other change in the script except on open/end open and set to choose file.

Am I missing something (not surprising). Or should I report this to Panic as a bug (if they’re concerned about 3 now that they’ve released 4)? How can I check the progress log of a script errors when using “on open” and not running it from the script editor?

-Chris

on open theFile
--set theFile to choose file
	set fileInfo to info for theFile
	set theServerAddress to "my.server.com"
	set theUserName to "username"
	set thePassword to "password"
	set theDirectory to "/my/path/"
	try
		tell application "Transmit"
			set SuppressAppleScriptAlerts to true
			tell current session of document 1
				connect to theServerAddress as user theUserName with password thePassword with initial path theDirectory
				upload item theFile with resume mode replace
			end tell
		end tell
		display dialog "Connected"
	on error
		display dialog "There was a problem"
	end try
end open

the result of choose file is one alias
the parameter of on open contains a list of aliases, even there is just one file.

I guess that’s the reason for the different behavior