I don't know exactly how to replicate it in our environment, but it appears to only happen after an autofit operation is done on all the columns. After attempting to resize a header column, the row columns become misaligned.
See the attachment for an example of what I'm talking about. It also happens if I simply place my mouse cursor so that it changes to the "resize column" pointer vs. the default pointer and move the pointer down.
Has anyone experienced this before and, if so, how did you resolve it?