Thanks for catching it. I create the strip in PShop which doesn't have a spelling checker. Typically each strip goes through many revisions until I think I've got it right. During the edit process, usually late in the evening and after a couple of glasses of wine - the typos creep in.
Tell you what, Gordo, you send me your strips after a few glasses of wine and I'll proofread them after a few glasses of gin and tonics. Together we could create a beautiful mess.