New line in a table get wrong text-formatting, making odd exception from the Paragraph style

I tink I have set upp my tables with al the right defintitions of Tablestyles, Cellstyles, Header rows, Paragraphs styles and removed any Charcter styles. Have also removed any overrides. Are working with anual reports in InDesign so I do a lot of tabels.
Everything works fine until I ad a new row. The new row get the right styles BUT the Pharagrap style get en override "+" sign and the text has got wrong formating, like italic instead of regular or other colur or size.
It is easyly fixed by "remove overrides" in Paragaraph Style but still werry annoying. When using a tablestyle you expect a new line to use the styles you'we set up. It is only the Paragraph-style setting that got this hickup, the other formating, like stroke, fill and so on works fine.
Is this a bug or is there something I'm doing wrong?
Hoping for a helpfull reply.
/Kattis