I think this might be caused by a new bug in Chrome or something since it seems to have popped up in GMBinder as well in the last couple weeks. See #683
Anyway, the error only occurs on the Class Table and Descriptive Text Box, which are also the only ones to use `border-image-repeat: round`. I changed it to `border-image-repeat: stretch` which solves the graphical issue and doesn't affect the appearance otherwise in this particular case.