Firefox + flashplugin-firefox - 0.4.10_3 error

hello,

does anybody use firefox 1PR with flashplugin-firefox from ports? if i 
compile and install it, firefox after i navigate to any page containing 
flash ends with this message terminal:

The program 'firefox-bin' received an X Window System error.
This probably reflects a bug in the program.
The error was 'BadShmSeg (invalid shared segment parameter)'.
  (Details: serial 26 error_code 151 request_code 143 minor_code 2)
  (Note to programmers: normally, X errors are reported asynchronously;
   that is, you will receive the error a while after causing it.
   To debug your program, run it with the --sync command line
   option to change this behavior. You can then get a meaningful
   backtrace from your debugger if you break on the gdk_x_error() function.)