On Tuesday,  9 Jan 2018 at 18:58, James Harkins wrote:
> I have several org documents containing source code listings, with
> references such as the following:

[...]

> Well, there is no label orgsrcblock1, so the exported document shows
> "??" instead of a listing number.

Check org-latex-prefer-user-labels.

-- 
Eric S Fraga via Emacs 27.0.50, Org release_9.1.6-317-gc82c21