Dr.. Watson

I am facing problem with the application installed like Oracle Developer 6 with Patches.. Know when ever the User is using this tool.. In reports when he click the preview button Dr.Watson comes..?

I have logoff from his account and logged in to Administrator.. now. No Dr watson on preview of that report..

SO I deleted his profile and then he logged on and automatically new profile created.
Now in his login the reports preview is working properly. I have solved the problem,

My actual question is What thing must be responsible for Dr. Watson.. And After deleting profile.. Everthing was running smooth..

Would u help me out of this dilema. ?