Version:           2.0.0_devel (using unspecified)
Compiler:          gcc 4.4.1 
OS:                Linux

While demoing kst2 recently I came to a situation where I could no longer see any curves! I have now been able to identify and reproduce the problem: it is linked with the changes not applying correctly in edit multiple curves mode. It was pretty hard to find out what was going on, hopefully it will be easier to fix! 

To reproduce:
- start kst2 and load two columns from gyrodata.dat in two plots
- in the first plot, double click => edit curve dialog
- click "Edit multiple", select all
- click "Show Points" => first buglet, the density combo is not activated
- click "Show lines", which activates point density (??!?)
- Density: select "High"
- click OK: all curves disappear! Try to get them to show again: not so easy, and yet the vectors are OK.
- double-click the first (empty) plot: notice that the curve is ignored in range calculations (checkbox at the bottom)
- uncheck the checkbox => the curve is back
- do the same with each curve, it will work. But unchecking the box with "Edit multiple" and "select all" does not solve the problem...

It is also possible to get a similar problem more easily:
- start kst2 and load two columns from gyrodata.dat in two plots
- in the first plot, double click => edit curve dialog
- click "Edit multiple", select all
- change the curve color in Appearance, click OK => all curves have the same X axis vector!