mozplugger 1.6.1 issue with mozilla 1.7

I upgraded to Mozill 1.7.3 from 1.2 on linux RH9. The mozplugger 1.6.1 
plugin now hangs windows with an embedded video.

The player runs successfully and completes, but the window M-spinner 
keeps running the whole time and an hourglass follows the mouse pointer 
on the page. Trying other URL links on the page does not work. Closing 
the window is the only recourse. Other windows are not affected.

It looks like a (recent, since 1.2?) change to the mozilla plugin API 
behavior prevents other user interaction within the window while the 
plugin is busy.

Near as I can make out, looking at the mozplugger source, the mozplugger 
basically hands off the stream URL to a helper app to display in the 
embedded subwindow, and then pretends to consume the stream (but no 
NPP_Write's are received?) until the window is closed. When the window 
is closed the plugin gets a NPP_DestroyStream and cleans ups the long 
spent helper zombie. The behavior change appears to be that Mozilla does 
not allow user interaction with the window while the plugin "pretends" 
to consume the stream.

I submitted a bug against mozplugger,

http://bugzilla.mozdev.org/show_bug.cgi?id=7296

but I thought the folks here may have an idea about the cause and how I 
might restructure the plugin. I have not done plugins before, but am 
willing to try a fix.