Problem Description : plugin150 trace file gets appended with the JPI log trace rather than creating a new trace file each time a new browser session is invoked.

Tested_Java_Release : Deployment PIT Build 01 for 1.5.0 (Tiger)
Tested_Build : J2RE.exe / J2SDK.exe
Tested_Build_Location : /net/sqesvr/deployment3/tiger/PIT_builds/test
Tested_Machine_Name : Windows XP(jd-sqe-lab2) / Windows 2000 (lemonade)/win98
dnm-dtf-025 (Solaris 8)

Steps to Reproduce :

1.) Install the 1.5.0 j2re on any machine from the above mentioned location
2.) Launch the below mentioned applets
    http://sqesvr.sfbay/deployment1/mantis_ws_plugin/doc/proc/JPI_bat.html
3.) Make sure you can see the test status in the JPI console
4.) Now close the browser and open the plugin150.trace file and you would
    see the results printed in the JPI console.
5.) Now once again launch the browser and run the above mentioned tests
6.) After completion of the tests open the plugin150.trace and you could
    see the trace being appended rather than creating a new trace file.

Result : This is a big impact for the users who depend on the trace file to debugging purposes and also JPI automated tests report gets corrupted as it depends on the trace file.

Note : I have attached the plugin150.trace file with this bug report.