Issue: Problem with VMs

It happens completely at random. When I'm reading VMs and go to reply, I either hit 'VM's' which should take me to our conversation, or I click on the other person's username to take me to their profile. I get the following two errors at random when doing this.

1 - When I click on VM's, instead of taking me to the conversation page between myself and them, it takes me back to the main forum page (http://aarinfantasy.com/forum/forum.php)

2 - When I click on the other person's username, I get the following error message: This user does not exist, and does not have a profile. That's not the exact message, because when I went to do it again to make a screenshot of it, it decided to start working.

Next time it happens, I'll try to remember to take a screenshot of the error message, in regards to the second error that I get.