Vanda flower problem - petal deformation

[Dorsetman]

I have a problem with several vandas which are all in flower at the present time. One of the two petals is deformed - or maybe it is just not in quite the correct position - being twisted out of the proper place. This one plant ( Vanda coerulea alba x Bangkok Sunrise) serves to illustrate this. As you can see there are two spikes, making a total of something like a dozen flowers, so the plant is generally growing quite well. On one pic I have added the letters S and P. I am talking about the petals marked P - and you can easily see what I am talking about. A flower on the other spike, in the bottom right hand corner is similarly deformed. I will come back to the dorsal sepal marked S later - but for now, I have never seen this petal deformation before , I have it on several plants all in flower at the current time, and all have previously flowered with perfect flowers.
So why ? Damage from a spray ? I have been using new things ( recomeded for orchids, but not used by me before ) to try and control the last remants of the scale problem which bothered me last year . Or some kind of temperature damage ? Some event surely - which happened at the time all the buds concerned were at a particular stage of development ? Any thoughts orr comments anyone ?
I will just deal with that fluted top or dorsal sepal marked P - this particulatr Vanda is inclined to do this ( none of the others do) if not grown really well. I think this plant must have been fairly well grown this year to give two spikes and a dozen or so flowers, many of which are perfect in all respects , so I leave this out of the question.
Another of the plants behaving in exactly the same way - deformed petals on one only of the two petals, , btw, is Ascda Oriental Siberian - posted in the Vandas in flower forum later today, although there I have taken care to choose a viewpoint which avoids the flaw being clearly seen.