Component returned failure error window

Component returned failure error window

I am getting Component returned failure error intermittently while working on Zoho Writer.
It happens on both SSL and non-SSL connections. I need to Force Quit Firefox as Firefox completely stops responding once I get this popup window.

My environment:
Firefox 3.0.3 OS X 10.5.5

Here is the error message that pops up: (I've attached screenshot of the board didn't allow me to paste the error code it generated)