Switching folders in KMail takes a while?

[kwhiskerz at gmail.com (Petrus de Calguarium)]

Martin Kho wrote:

> When I for the first time switch in KMail from one folder to 
another it
> takes a few seconds before the content is shown.

I also notice this since about a week, roughly. It seems to be 
when I try to look at the contents of the sent directory.