[whpalmer4]

It's often a bit easier to debug someone else's code when you can actually see it :-)

A context is not assigned by assigning the name of the context as you've done here. You have to use the actual context object associated with that name.

Here's a small example which creates a test item in the Miscellaneous project with context Home (using the parse tasks verb), then finds the context Office and assigns it to the test item instead of Home.

tell application "OmniFocus"
	tell front document
		set mytask to first item of (parse tasks with transport text "test item > Miscellaneous @Home")
		set mycontext to first flattened context where name is "Office"
		set context of mytask to mycontext
	end tell
end tell

The "flattened context" bit allows you to find a matching context even if it is nested inside another ("Errands : Office") whereas the same statement without the "flattened" adjective would only find items at the top level ("Office").