On current builds of 1.4.2 (b16) and 1.5 (b2), I've obversed jtreg to fail on linux when running the BigInteger regression tests if the tests are specified as "*.java"; strangely, everything works fine if the tests are specified as ".". Run individually, the tests also all pass. Somehow, the file globbing seems to be involved. Sample failing stack trace:

TEST: java/math/BigInteger/ModPow.java
java.lang.StringIndexOutOfBoundsException: String index out of range: -1
        at java.lang.String.substring(String.java:1438)
        at com.sun.javatest.regtest.Main$RegressionObserver.getTestJDK(Main.java:580)
        at com.sun.javatest.regtest.Main$RegressionObserver.printOutput(Main.java:433)
        at com.sun.javatest.regtest.Main$RegressionObserver.finished(Main.java:403)
        at javasoft.sqe.javatest.TestRunner$Notifier.finished(TestRunner.java:282)
        at javasoft.sqe.javatest.TestRunner$Worker.runTest(TestRunner.java:257)
        at javasoft.sqe.javatest.TestRunner$Worker.run(TestRunner.java:210)