FULL PRODUCT VERSION :
1.6.0_14

ADDITIONAL OS VERSION INFORMATION :
Windows XP SR-3

A DESCRIPTION OF THE PROBLEM :
After VM start-up, sun.nio.cs.ext.ExtendedCharsets may be customized according system property "sun.nio.cs.map".
If a charset is yet cached in java.nio.charset.Charset before VM start-up finish, it will remain there, causing that customization by system property "sun.nio.cs.map" has no effect.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
- Set sun.nio.cs.map="Windows-31J/Shift_JIS"
- Invoke Charset.forName("Shift_JIS") before sun.misc.VM.isBooted() returns true
- Invoke Charset.forName("Shift_JIS") after sun.misc.VM.isBooted() returns true
- Check charset object's name() methode

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
windows-31j
ACTUAL -
Shift_JIS

REPRODUCIBILITY :
This bug can be reproduced always.

CUSTOMER SUBMITTED WORKAROUND :
class java.nio.charset.Charset should have interface to clear it's cache, that could be invoked from charset provider in case of update.
or:
interface java.nio.charset.spi.CharsetProvider should have method, to determine, if the charset provider is finally initialized.