Bacterial or fungal...or something?

[ula]

Hi, recently I've noticed this yellow lesions appearing on dendrobium canes. At first I thought it was just mechanical damage, but under scrutiny I discovered, that once the lesion dissapears, it leaves a pit filled with necrotic tissue. What is it, and should I be concerned?

Here you can see the "injury" on the tip of the cane, and a small, yellow leasion on the cane directly under it,



this is what the lesion looks like (sorry for the poor picture quality), and the damage on the base of the cane.
Please help!
Ok, better pics?

Here rotted pit on the base of cane on the left, next pic the same damage bottom right,
and here's the yellow lesion.

Any takers on this one?