Roundover finishing - what's causing this..?

[Wal]

Hi,

I was making a little wooden ornament for a friend earlier and I noticed a bit of 'roughness' on the final round-over pass.



It sands out reasonably well, but I'm curious to know what's causing it - I thought it might be a conventional/climb issue, but the weird thing is that it happens in the same places regardless of whether I'm climbing or cutting conventionally. The areas where it isn't happening are nicely finished and the parts which bear the rougher finish have one thing in common (and this surely has to be a clue) - they're oriented the same way...

So, is it feeds/speeds, is my round-over bit a bit rubbish (admittedly it is), or is the wood itself contributing to the finish?

Cheers!

Wal.