Those are typos, Voronwe. Please go ahead and make the changes. The comma instead of the semi-colon is OK with me, however, the semi-colon is technically correct. You can use 'however' instead if you want.
Jn
edit: ah ... I'm trying to clean up my desktop here, so I used the 'comma however' construction because it's a bit more elegant. If you want something different, tell me here and I'll edit the Actual Document thread.