When trying to apply a patchlevel the installer does not start, instead an application event is recorded:
The application, E:\Depot\jre-6u33-windows-i586.exe, generated an application error The error occurred on 09/24/2012 @ 14:52:26.713 The exception generated was c0000005 at address 002F88D0 (<nosymbols>)
This occurs if DEP is enabled ( /noexecute=alwayson for W2K3 R2 x64)
The 64bit installer (p:\Depot\jre-6u35-windows-x64.exe) does start and installs successfully.
To start the installation /noexecute has to be set to OptOut (but without adding jre-6u33-windows-i586.exe to the exception list).