Cherry Blossom Tree Secreting a brown jelly of the leafs???????

Hi all. I have  had a cherry blossom tree for some years now. It has never failed us with great blossoms up to now. The flowers and leaves have a brown jelly substances dripping of them can anyone tell me what this might be and do I need to take action!!!

Here is the RHS page on bacterial canker.

It says that the ooze comes from the stems of the plant, not the leaves.  The symptoms on the leaves are holes where dead small areas drop out. 

Have a look to see whether it matches your symptoms or not.

http://apps.rhs.org.uk/advicesearch/Profile.aspx?PID=86

I'm not sure what else it might be, though.