We use 2 different makes of the Mini Pro.
Thank you very much for your help Mike!
This is only on one strip, my other strip with the same code is perfectly fine.
and the one not working right when dimmed down running off a plug pack
running off a lab power supply with no capacitor or resistors yet,
I am assuming that a plug pack is some sort of power supply.
I am also assuming that the ground of this plug pack is also connected to the ground of the Arduino and the +ve is only connected to this second strip.
Well put them in as soon as.
I haven't checked is it's regulated or switch mode... I know it's not an unregulated supply though.