This is one of the current issues of DT registration that need to be checked and verified with the updated implemenation of jre installtion

Issues: The higher version of IE DT plugin is being replaced by the lowever

*** Tested Configuration
- x86 XP(sp3)/ IE 8

*** Steps to reproduce:
0) Make sure no IE DT plugin on the system (\system32\deployJava1.dll)
1) Install 6u31-b02 (current promoted build)
2) Install JavaFX 2u2 runtime
At this state, \system32\deployJava1.dll has the version 10.2.1.x (which comes from JavaFX 2u2)

3) Install 7u1-fcs

If you see \system32\deployJava1.dll has the version 10.1.0.8 (which comes from 7u1), then the issue is producible (Expected deployJava1.dll version 10.2.1.x)