I recall I'm the one who tried to teach you how to create links, and it looks like I haven't done a very good job. I'll try to explain again.
Let's say I want to link to my pet, and the URL for their profile looks like this: http://beastkeeper.com/pet/483081. I select the text I want to use for the link (for example, "this pet"), and paste http://beastkeeper.com/pet/483081 into the box labeled Link URL. So it creates this: this pet
I'm not sure how you're getting the URLs you're using for links, but they're not correct. In your most recent post, you linked http://beastkeeper.com/user-post-list/beastkeeper.com/pet/656054, when you should have actually linked http://beastkeeper.com/pet/656054. Make sure you're only putting one URL in the Link box.
Edit: Okay, learned something new. Looks like you can also create a link just by copying and pasting the URL directly into your post without opening the Insert Link window.