Evolution doesn’t really tell you that when you use a script to generate your signature you need to terminate the lines with a ‘<br/>’, otherwise it pretends that there hasn’t been one.
All to do with html mail composition. The only way I accidentally found this out was because of it’s gconf entry containing this gem:
<?xml version="1.0"?> <signature name="default" uid="XXX@XXX" auto="false" format="text/html"> <filename script="true">sig.work</filename> </signature>