Can you post a photo?

It sounds like a fungal infection to me. If it looks like it is spreading you can use either cinnamon or horticultural sulfur to stop it. If the infection does not spread or become yellow around the spots it is most likley not a serious problem. Fungal spores are all around us all the time and sometimes if they have the right conditions such as a wet leaf surface and the right temperatures they can germinate and cause infection which usually shows up as a black spot that can spread and turn yellow killing the leaf.

Are only a few leaves affected on each plant? Some Hoyas naturally have black spots on the new leaves, my Hoya acuta has many tiny black spots on the undersides of the leaves while the are developing but that is natural an nothing to worry about.

Mike

Hey Mike, if you use cinnamon,how do you use it, ie, sprinkle on the dirt, leaves or mix with water?

Thanks,

Dee

Mike,
So far the spotting doesn't seem to be a serious problem. However, I will keep a close eye on them. I've already spread cinnamon mixture on the leaves as a precautionary measure. I'm not sure how good the coverage needs to be.
Thanks.

As to posting pictures, it's a major pain.It will only be attempted as a desparate measure.

Sande

I just sprinkle some cinnamon on wet rot but as another forum member mentioned recently mixing cinnamon with water to form a paste works well for other times when dry cinnamon would not stay put.

Posting photos is easy if you open a Flickr account or Photobucket. All you need to do is upload your photos and then copy the URL or HTML lines that are provided, sounds difficult but I promise it's not once you get the hang of it.

Mike