I had this before the latest patch as well.
At first i thought it had something to do with the buckler, but then i had the same issue with the bigger round shields, too.
These are my two major "wth" moments.
visitors can't see pics , please
register or
login1.) This happens sometimes, if i try to get past someone at a quite close distance. Could be a clipping issue, because i have this sometimes against extreme facehuggers as well.
2.) Here i have no clue. The opponent stands at my side and performs a wide swing, which goes through my shield and hits me.
Maybe it is the same think like with the kicks.
The others say that they have hit me, while i have seen them miss.
Anyway, my main gripe is still, that my shield becomes non-existent when i release the right mouse button. I whish that there would be something like a negative block delay.