All running JNLP applications are combined into one group on Windows taskbar

FULL PRODUCT VERSION :
java version "1.8.0_40"
Java(TM) SE Runtime Environment (build 1.8.0_40-b25)
Java HotSpot(TM) Client VM (build 25.40-b25, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 6.3.9600] (Windows 8.1 x64)
Microsoft Windows [Version 6.1.7601] (Windows 7 x64)

A DESCRIPTION OF THE PROBLEM :
When running JNLP applications, all application windows across all JNLP applications will appear "grouped" together on the Windows 7/8 taskbar, even if the applications are completely different and from different websites/locations. This bug does not seem to affect Java applications that do NOT use Java Web Start, they will still appear ungrouped.

To define what I mean by "grouped", look at how the different Explorer windows appear on the taskbar. If you move one of them around on the taskbar, they all move as one group. If you have many windows open, then they are collapsed into a single icon. To select the desired window, then you must click/hover on this, and then you can select the Explorer window you want.

Contrast this by opening up Notepad and Calculator. They appear as completely different programs on the taskbar. You can move them around independently and they will never collapse together.

REGRESSION. Last worked in version 7u65

ADDITIONAL REGRESSION INFORMATION:
Last working version found:
java version "1.7.0_60"
Java(TM) SE Runtime Environment (build 1.7.0_60-b19)
Java HotSpot(TM) Client VM (build 24.60-b09, mixed mode, sharing)

Tested on a few versions to figure out when the bug was introduced (all freshly downloaded from Oracle's website, all tested on a fresh install of Windows 8.1):
Worked okay:
jre-7u40-windows-i586
jre-7u45-windows-i586
jre-7u51-windows-i586
jre-7u60-windows-i586

No longer working as expected:
jre-7u65-windows-i586
jre-7u67-windows-i586
jre-7u71-windows-i586
jre-7u72-windows-i586
jre-7u75-windows-i586
jre-8u40-windows-i586

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run two unrelated JNLP applications by double-clicking on them locally, or run them from a website, either by downloading the JNLPs or having them run using the deployJava.js script. Run them in any order with any timing you'd like.

Here are two from Oracle's website:
https://docs.oracle.com/javase/tutorialJWS/samples/deployment/dynamictree_webstartJWSProject/dynamictree_webstart.jnlp
https://docs.oracle.com/javase/tutorialJWS/samples/deployment/customprogress_webstartJWSProject/customprogress_webstart.jnlp

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The different/unrelated application instances should appear as separate, ungrouped applications on the Windows taskbar.
ACTUAL -
The applications are grouped on the Windows taskbar.

REPRODUCIBILITY :
This bug can be reproduced always.