Allow me to explain by showing you this picture:
As you can see, it is a picture of my Windows 7 taskbar, no modifications made.
Now let's take a look at the right 3 active Icons. You have Navicat (the greenish icon) running, note that it has 2 windows open. Next is Notepad, I've opened 3 instances of notepad as you can see, it's grouped together.
Now for my last one, NetBeans (the blue cube). Only this time, after opening NetBeans by clicking on the taskbar shortcut. It opens NEXT to the icon, instead of merging with it like we've seen with navicat and notepad. If I click the left one (the shortcut) it simply opens the already running NetBeans, and if I click the right one (the active instance) it behaves exactly the same, it simply opens up the already running instance.
Why is this application not merging with the taskbar? How can I let it Merge? And why doesn't it let me open up multiple instances of NetBeans when I click the shortcut? Please provide me with a way to at least solve the merging problem, as a perfectionist I can't sleep at night because of this brutal flaw within the taskbar.
PS: I already tried middle-clicking the icon to open up a new instance but it's not working.