The forum button dissapaers every now and again?

I have started noticing the forum button has been dissapearing every now and again after I post a new topic or post to a topic and then reapears several minuets latter. I have not been able to replicate it on will but it will happen randomly like a program is crashing that runs it maybe? Any help? http://dscompforums.tk

Manged to catch it got a screen shot:

Have to think about that one and what would cause that to happen.

If it helps it seems to happen more so when I make a new topic.

It is still happening.