It's a mistake on our part- sorry for that. There are times when they can't be used synonymously, though. (In this sentence, I have used 'though' in end position without a meaning similar to 'however'- you couldn't replace it with 'although')
In addition, historically, the adverb all was used with the conjunction "though", and often the order was reversed, producing "all though", later "although", originally an emphatic form of though. Source: randomhouse.com
"although" and "though" are often used interchangeably as a subordinating conjunction, but The Keables Guide (to Good Writing)recommends using "although" or "even though" as a [subordinating] conjunction and "though" as a transitional adverb set off by commas:
EX: Although it rained, we went on with our plans.
EX: The rain made it miserable, though, and we regretted our decision.