When deleting/closing plugins in the mixer other plugins open

[Carbinax]

This has been bugging me for a while.

In the mixer, on the plugin slots for a particular channel, there are some coloured dark grey, and some coloured the default lighter grey. I dont understand why this is.
Whenever I open an effect to adjust it, and then X out of it, one of the plugins in the list above it will open. I dont want it to open.
This can happen up to 4 or 5 times one after the other sometimes, and its irritating.
When I delete a plugin, another one opens, and a lot of the time I'll click on an effect, and one of the dark grey ones opens instead.

Is there any reason for this and how can I stop this happening ??

Im thinking the dark grey ones are possibly last opened, and i'd like to turn that off if I can.

An example : in this screenshot, I clicked on the parametric eq at the bottom, and the multiband compressor opened instead

weird plugin behaviour.jpg

It was a minor irritation at the start but now its really annoying.

Any ideas ??

[FidelityMusic]

Hello Carbinax, The darker FX slot indicates a...

[Carbinax]

Brilliant Fid. Never really paid much attention...