When I open some applications with their own splash screens sometimes they come up, other times I just get a white empty window. I cannot see any pattern, it's not, for example, that it shows only on the first time I open it each boot as I once thought.
In particular I have noticed this with K3B from the repo and Vuescan installed locally.
I'm using a fully updated LXDE with quite a lot of KDE3 bits installed as well (as required to make other programs work)
Not a serious problem, but clearly a minor bug of some sort.