Yes, I use a custom german language file (The forum is completely integrated with WP i.e. both configurations are loaded).,
I just tried posting links while not using the language file: no change, href still gets stripped.
Deactivating all my plugins doesn’t help either.
Also, for some reason ” does not get unescaped. I get ” all over the place. This I was able to fix with a custom stripslashes-filter. Its strange though that forum software comes with such bugs out of the box…
The href must be stripped when saving a post, as it does not appear in the database tables. Some pre_post filter maybe?