I've tested with both with Sun's Java 1.5.0_17 and 1.6.0_11, the result were all the same after I rechecked and reconfigured my system. The system was on Linux Debain Etch, perl 5.8.8, Inline::Java was 0.52. So that's why I'm still wondering about if my perl code was not correct since two of the three function call will work.