RemoveAssociation with File and Extension is failing in solaris.

This works fine in Windows but fails in Solaris.

here is the testcase :
http://nicole1.sfbay.sun.com:8080/JavawsMustangIntegTest//integrationService/RemoveMimeAndFileExtnAssociation.jnlp

Test Code:
String mime = "x-application/abc";
        String []exts = {"abc"};
        boolean result = is.removeAssociation(mime,exts);
Expected true but returns false.

Reproduced machine: urts071.india.sun.com:1 vncpassword: vnc123.
JAVA_HOME in that machine : /net/sqindia.india/export/java/re/jdk/6u18/promoted/fcs/b07/binaries/solaris-sparc/
Affected TestCases : 6
Reproduced machine: urts071.india.sun.com:1 vncpassword: vnc123.
This machine is having a supported gnome version 2.6.