Thank you for your post.
I am unable to replicate this issue starting with Enlightened Theme and moving between all other Themes.
Which Theme are you using as a starting reference? Which Theme are you changing to and then back again?
The files were originally created in FM 11 then moved to FM 12 and finally to FM13. More testing today and I can only replicate it once in the file you were using previously. It is the cause for so many fields having a placement of x.xx pix. I won't have time for a few days to go back to the damaged file with the container problem but I will be able to get to it later in the week.