Is there any way to inject own code into QTP's 11 Extension for Firefox

I'm still fighting with HP QTP 11: Script execution fails when running in Firefox, but Debug Viewer shows result of operation

By entry in Firefox Error Console I see what files are used to perform interactions by QTP:

Error: obj[FuncName] is undefined Source File: file:///C:/Program%20Files/HP/QuickTest%20Prof开发者_JS百科essional/Bin/Mozilla/Common/components/ScriptWrapperXPCOM.js -> file:///c:/program%20files/hp/quicktest%20professional/bin/JSFiles/mzDotObj.js Line: 76

So, as a possible way to find solution why script execution fails, but debug viewer and using of "eval" function works, I want to put some debug points in those JS files and see what happening. I tried to put alerts into mzDotObj.js, but looks like Firefox don't see the changes (or ignores alerts?). I tried to restart firefox, to do hard-refresh (Ctrl+F5 and Ctrl+R). So, is there any way t debug those js files, that qtp uses to interact with firefox.

Thank you!

Firefox caches XPCOM compoments and JavaScript modules ("fastload"). You need to ensure that the cache is ignored when you make your changes. In current Firefox versions you run Firefox with the -purgecaches command line flag. In Firefox 3.x you need to add a boolean nglayout.debug.disable_xul_cache preference and set it to true.