deformed flowers

I've noticed some deformities in a few flowers over the last few weeks, just one or two here and there. Not a big deal but I'm curious as to what is the cause. One bud (looks healthy) coming through on Munstead is actually growing through a flower. Very strange.
Has anyone noticed any flower deformities? Is it seasonal? Should I be concerned?

Do you have any photos......it might be easier to work out for you.....

That sounds like proliferation.

I don't know what causes it but apparently some roses are more prone to it than others.

Sounds more liek a genetic thing than proliferation, which is icky vegetative centres. Found this about double-storey rose - an 'oops of nature' they call it ;-):

Another of the causes of rose deformities is really just a genetic effect, otherwise known as “an oops of nature.” These may include such things as several leaves growing together to form what appears to be one big leaf or having one bloom growing directly out of the center of a current bloom.

Ahahaha, oops of nature love it!

I'll try to get some photos tomorrow. The two roses concerned are Ashram and Munstead Wood. Having come at the same time I'm wondering whether seasonal or climatic conditions might be a trigger. I haven't seen this in any of my roses before so I am a bit intrigued.