[somedude]

Just in case it helps, here's what the lines in question look like after modification:

	if my onlyShowOmniPlanFilesInOpenDialog then
		set sourceAlias to choose file with prompt "Source project to import contents from:" of type {"com.omnigroup.omniplan.planfile"} without invisibles
	else
		set sourceAlias to choose folder with prompt "Source project to import contents from:" without invisibles
	end if
	
	repeat with thisFile in (items of sourceInfo whose kind is "OmniPlan")
		-- sneaky trick to prevent quirks that occur when two OmniPlan files have the same uuid. Generate a new file using the original as a template will force a new unique id. 
		set thisFile to info for sourceAlias
		if kind of thisFile is "OmniPlan" then
			set t to POSIX path of sourceAlias
			set sourceDoc to make new document with properties {template:t}
			set sourceName to name of thisFile

... and I ended the repeat before the end tell on the last line of the script.

Thanks for all the help.