Tested in scenario auto updating from
6u21-b07 -> 6u22-b01

JDK/JRE tested: 6u22 b01
OS/architecture: Windows
Reproducible: Always
Reproducible on machine:
Is it a platform specific regression: Y(Windows only)
Is it a new platform support: N
Is it a Regression: N
Regression introduced in release/build: Not a regression

1) Install 6u21 b07
http://jre.sfbay.sun.com/java/re/jdk/6_21/latest/bundles/windows-i586/jre-6u21-windows-i586-iftw-rv.exe

2) After 6u21 b07 installation is complete, install 6u22 b01 -
http://jre.sfbay.sun.com/java/re/jdk/6_22/promoted/ea/b01/bundles/windows-i586/jre-6u22-ea-windows-i586-s.exe

3)Open registry key
 HKEY_LOCAL_MACHINE\Software\Javasoft\Java Runtime Environment\1.6.0_22\MSI
 Check the value of Mode if its 'C' PIP didn't take place.

It should be 'U' if the Patch-in-Place worked as expected.
6u21-b06 was already fcs but was not included 6u22 build 01 promotion.
Auto-update from 6u21-b06 to 6u22 b01 also failed.