Flash in Firefox results in X Window System Error

[Dennis Jacobfeuerborn]

Alan Coopersmith wrote:
> Dennis Jacobfeuerborn wrote:
>> After upgrading the X11 libraries in Fedora Core Rawhide yesterday 
>> Firefox now crashes with a "X Window System Error" everytime I load a 
>> page containing a flash applet:
>>
>> Gdk-ERROR **: The program 'Gecko' received an X Window System error.
>> This probably reflects a bug in the program.
>> The error was 'BadMatch (invalid parameter attributes)'.
>>   (Details: serial 120 error_code 8 request_code 146 minor_code 3)
>>
>> What is the proper way to decode the error numbers above into 
>> something human readable?
> 
> It helps to not have your toolkit override the default X error handlers
> which print human-readable names, but that's a story for someone else.
> 
> For "request_code 146", since it's >128, it's an extension, for which
> codes are dynamically assigned based on which extensions are being used
> in your configuration - you'll need to run "xdpyinfo -queryExt" and look
> for an extension line with opcode 146 to see which one that is.

xdpyinfo says opcode 146 is the MIT-SHM extension. So far I've done the 
following to find out which package caused this:
1) I've downgraded glib2 to a known good version
2) I've recompiled Xorg with your fpic patch removal reverted
3) I've downgraded gtk2 to a known good version

None of this helped though. I was also thinking about downgrading LibX11 
and libXt (based on the backtrace) but they haven't changed in a while so 
it's unlikely that they are the cause for this. Do you have any advice on 
how to actually find the offender by debugging rather than poking at more 
or less random packages?

Regards,
   Dennis