Xlib : unexpected async reply

       Iam buildin a kde Application that uses Xlib .
       Iam using  pthread_cond_wait() so that the running
       worker thread will wait untill the GUI thread give
       signal or finished his work .

      But suppose the worker thread blocked some X resources and waiting
      for the signal . If the next thread need those resources
      then there going to be problem .
      So in my case how will ensure that blocked working thread will
      release   all the X resources so that the GUI thread can
      use that X resources .I have used separate display connection
      for each thread .

     I pause the current pthread and invoke an dialog in
    another thread the following error is coming
:
 >    Xlib : unexpected async reply
>    Xlib :    sequence lost (0x1718e > 0x71a0) in reply to 0x0!
>    X Error : BadImplementation (server does not implement opertaion) 17
>     Major opcode : 20
>     MInor opcode : 0
>     Resource id  : 0x759d1
> The error is coming randomly , not always .
   Can any will help how to come out of this error .


Thanks