The issue is a minor one, but has not appeared (literally) before now. I find no space between a table caption and the table beneath it. This lack of space is seen both in the LyX window and the pdflatex-compiled document. My remedy is to add \vspace{10pt} on a line between the caption and the table body. This works for me.
The bug shows up when I check spelling and causes the application to segfault and crash. If someone provides me with a pointer how to save the source of the problem I'll be happy to pass it on to the developers. I don't suppose it can be seen in the .emergency file that I reload when this occurs. Rich