Botrytis, perhaps?

Here is a link that might be useful: botrytis pictures at sactorose.org

Probably thrips. Once the weather heats up a bit more, they will probably subside. If you use the "search" function and enter "thrips" you will find many threads that may be helpful.

Here's a link with a picture of a thrips damaged white rose. Familiar?

Here is a link that might be useful: Thrips

Can you post a picture of the problem flowers? Without that it's difficult to say for sure what your problem is (although thrips is a common problem).

Sounds like thrips to me.