Strange
They are all DDS files right, not JPG?
I know that some of those have more than one (the stock folders have 5 each), so you have more than 38 total.
I bet that is why you got that 123 count or whatever it was.
Try removing some in case there are too many, like the ones with the special characters.
Like Sids_Sky-Pack v1.0b
rolfy_skies
KU-315
If those folders have skies that you use alot, then go through and sort out others you don't use often.
Save them in your assets, but only have your top 100 skies in the program files for the slider.
I'm not sure what the cap is on those, but I can't image needing more than 100 skies at any one time.
Quote: "The 'sky value' jumps from 2 to 123, there is no in between value and only 2 skys are shown."
That sounds like the third sky is probably causing the problem if it is not the count being too high.
On second thought, maybe you should start removing them with the third one instead of those others mentioned above.