Illustrator Layers are expanded when opening.

Question

I haven't had much luck googling this, because I am not certain of the proper terminology to ask the question.
When I open a file, one or more layer are opened/expanded in the layer tab on the side of the screen.  I can close the layer, make modifications, and save; but when I open it up, the layer is always opened.
It doesn't happen with every file.  But on the files that do have this, it's always like this.
Any ideas? It's rathe annoying, especially with larger art files.

Answer 1

SOULTION WORK ARROUND HERE:
At a previous job at AARP.org, we had CS2 and went to CS4, where I first noticed this "bug."
Sometimes, we'd have a file with 10-30 web page designs in it and having to close all the Layers showinging every Sublayer drove  me nuts and can take a few Annoyed minutes.
I still have this issue in CS5, and noticed it yesterday on a co-workers CS6.
So, today I decided to Google search and fonund this thread.
I've spent the last 2 hours trying to fix the issue of all Layers and Sublayers showing when opening a document and I have found a work arround. 
Now, we know that Illustrator gives a unique color to items that live on seperate layers, and it also does this for Sub-layers.
It seems when you open a file with lots of layers and sub-layers, the defualt in Illustator is to show all layers.
To fix that bug they need to add a "Show/Hide Sublayers" or something.
I think they may have added "Sublayers" in CS4, and that is when this "bug" started for the users. I'm not sure.
Also, sometimes items are getting stuck inside sub-layers etc, and it becomes hard to move selected items to the front and or back using short cut commands, you have to actually go move the sub-layer. meh.
Somethings to note:
Adobe gives the user the option to "Merge Selcted Layers" but this only lets you merge layers and sub-layers that live within the same heiarchy, and you still will have lower level sub-layers, and you can't drag a sub-sub-level layer to the the sub-layer up from it.
I haven't figured out how or why all the sublayers got created, I know I never made a actual "New Sublayer"
So, if there is a process in the workflow to avoid doing that, I'll look out for it and post something in the future.
But it may have to do with working with custom symbols, pasting form layers to layers, Paste Remembers Layers being selected, copying layers, etc... I don't know.
So, here is how I cleaned up my file:
I removed all the damn sub-layers that ened up in my file somehow.
1) First make sure "Paste Remembers Layers" is NOT selcted in the Layers palette menu. 
2) Select everything in a specific layer by clicking on the circle to the right of the layer name in the layers palatte or use commed-c to copy.
3) With all your content still selected, delete everything.
4) Select all the sub-layers (which are now empty), that are underneath your most top level layer.
5) Click on your top level layer, and use Shift-Command-V to Paste in Place (also found under the Edit menu).
Now, your layers will look like the used back in CS3 or CS2, you will have NO Sublayers, and after you save and re-open the document, all layers will not be open showing.
Ta-Da! This has been driving me crazy for like a year and a half. Work arround discovered.
Thought I should share. 
Now, if you like using layers and naming them, then you're stuck with all layers showing upon opening a document but you can reduce what shows by going into Panel Options and checking "Show Layers Only"
This will show only your layers and sub-layers, but it can reduce you seeing all the paths and objects, etc., but when you open documents, all those layers will still be open. Got it?