Strange Behaviour in my Vbulletin
 

Actually this happened with my once before I upgrade into 3.8.2 in my vbtest, but I said may be it's just because I didn't sleep well.
today it happend with my in my main vb board

some times when I open a thread or any other link in my vbulletin board it opens a small picture instead of the link I tried to open it

so I don't know what's the reason, I wish to know if there is any thing that I should be aware of it.

***Update***

Ishould mension that I don't find the drop down lists in my navbar such as quick list & the Community list, they are only links even though the DHTML settings are on

regards :)