Since yesterday or the other day, there is a black block on top of the default forum view which also persists once you enter a thread so you the original post and sometimes the second one is completely obscured.
I am using an Android phone on Jelly Bean with an Opera Mini browser and it has been working fine up to this point.
also, try updating the browser on your phone, the support for Opera Mini is terrible. It doesn't support handful of techniques we use on the site.
I've heard from my friend front-end developer that Opera Mini is a hassle to optimize it for...However, this browser works the best for me. But on the other hand, I know one good work around -> enabling single column view.
There is yet another factor however, I think it is not possible to create a new thread using an Opera Mobile anymore.