[Elecraft] K2 - frequency control

[Nick Henwood]

I have just started to notice a click and a very small jump in frequency every 5 kHz on my K2. For example I find it on 30M:
10105.78
10110.78
10115.78
10120.87 (etc)

on 40M it appears:
7034.3
7029.93
7024.93 (etc)

Is this something that has always been there which I have just noticed ? I can work round it but would prefer not to. As usual I run the risk here of exposing my ignorance so please be kind if the answer is obvious!
73 Nick G3RWF