The character which Unicode is 03c5 cannot be rendered consistently on JTree component when running the test case JTreeRenderTest of GS-Manual for 6u7 b02(j4b bundle),
Please refer to attachment JTree.PNG for details.

JDK:jdkfb-6u7-fcs-bin-b02-windows-i586-p-10_apr_2008.exe
OS:Win_X86-Vista
Locale:zh_TW
Tools: GS-Tonga_12.zip
Original Tools Suite Location:
/net/sqe1.sfbay/quality2/i18n/workspaces/i18n_mustang_ws/i18n/bundles/b12

Reproduce:
1. install 6u7 b02 as JAVA_HOME.
2. unzip GS-Tonga_b12.zip.
3. setenv.
4. sh runnit.sh -keywords:"zh_TW&&manual".
5. turn the testcase to JTreeRenderTest.
6. Expand node "¿¿¿"->"¿¿¿" and select "¿¿" from JTree component.
7. Click munu "Tree"->"Add Children".
8. Select the new children .
9. Select "Metal","CDE/Motif","Windows" and "Windows Classic" from "LookAndFeel" one by one.

This problem is reproducible on both Win-XP and Win-Vista.
Also , it looks like to me that this problem does not exist on English alphabets "A-Z" and numbers "0-9" .
Please run the attachment jtreerendertest.jar to verify if nesessary . And the source code attatched as src_jtree.zip .

Please refer to attachment jtTest.PNG for details.