Editing your post and pasting the part inside the href and the url tag
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You can try this before pasting a link with "#" in the "middle":
create a url tag and paste the url like this:
[url=pastedURL]Name of the thingy[/url]
You can avoid writing a name and you can add the url there too

. If you only paste the url on the post without tags, will be the same as if you write:
[url=pastedURL]pastedURL[/url]
But it always need to have a name and will add it automatically as the linky text:). However, the Forum will parse it as can and you will end with unexpected results (talking about the last example).
Also, if you are going to post a tweeter link like the previous one you post, make sure you remove this part from your URL:
#!/
Then the forum will parse the link correctly.