When there are spaces in the attribute text, the document generator will know where to break these texts. If there aren't, then it won't know where to break so it will just keep going even when there is no space. You could insert a zero width space character (see http://en.wikipedia.org/wiki/Zero-width_space) to make it break manually.
At least this is the case in 2.5.4, I'm not 100% sure what the behavior in 2.5.3 was.
I have the same problems. I think this is a bug. You can solve this by playing with the widths of the coloms and the alignment!