This is a really annoying possible bug:

1. Create a table with some content
2. Select some cells e.g. a heading row
3. Click on the borders icon and set top and bottom borders

Result:
border are drawn okay but 
the cells get a spacing to contents of 0.1 cm applied
I then have to manually change back again to my original setting of 0.05
so that the contents are aligned with the rest of the table.

Perhaps I am missing something or being stupid, but clearly there is some default setting being applied if the spacing is <0.1, but there is nowhere to change this default setting (I have looked in the tools options, and in table and frame styles)

I recall in ms-word that if I set table cell settings for the first table they would get carried forward for all subsequent tables.

I use lots of tables so this is driving me nuts.