it might just be a miner who dont wants to include transactions... i dont know
it is also likely that there was no transactioins, between the last block and this, there was only 30s between them

You used to see a good amount of blocks getting pushed that didn't have transactions on them.  This wasn't because transaction volumes were low, mind you; these blocks could be ten minutes after the last blocks, with an average number of transactions per normal block above ten, and yet they'd still have zero transactions on them.  My best guess was that someone (or some group) was running custom mining software that didn't bother to include transactions on blocks (as it's harder to code in handling all of the additional transactions coming off the network than to just code a single generate transaction and be done with it).  With the network's huge growth in recent months, however, these "null" blocks have gotten a lot, lot less frequent, so whoever was doing them is becoming a much smaller part of the network percentage-wise.  All of the big pools are using proper software that includes transactions in the mined blocks, obviously.