SymUIAgent keeps writing & writing on my disk

I read the previous messages, so tried closing the process in Activity Monitor - it just restarts immediately. It keeps running my disk.

 

I have a Mac running Mac OS X (10.6.8).

I also read you are supposed to save a sample and post it here for Support, so you can see what's happening. Here it is:

Sampling process 250 for 3 seconds with 1 millisecond of run time between samples

Sampling completed, processing symbols...

Analysis of sampling SymUIAgent (pid 250) every 1 millisecond

Call graph:

    2586 Thread_3640   DispatchQueue_1: com.apple.main-thread  (serial)

      2586 start

        2586 _start

          2586 NSApplicationMain

            2586 -[NSApplication run]

              2586 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:]

                2586 _DPSNextEvent

                  2586 BlockUntilNextEventMatchingListInMode

                    2586 ReceiveNextEventCommon

                      2586 RunCurrentEventLoopInMode

                        2586 CFRunLoopRunInMode

                          2586 CFRunLoopRunSpecific

                            2586 __CFRunLoopRun

                              2586 mach_msg

                                2586 mach_msg_trap

    2586 Thread_3642   DispatchQueue_2: com.apple.libdispatch-manager  (serial)

      2586 start_wqthread

        2586 _pthread_wqthread

          2586 _dispatch_worker_thread2

            2586 _dispatch_queue_invoke

              2586 _dispatch_mgr_invoke

                2586 kevent

    2586 Thread_3645

      2586 thread_start

        2586 _pthread_start

          2586 ZssStString::operator=(ZssSymbol*)

            2586 mach_msg_server

              2586 mach_msg

                2586 mach_msg_trap

    2586 Thread_3648

      2586 thread_start

        2586 _pthread_start

          2586 __NSThread__main__

            2586 -[NSThread main]

              2586 0x255ce7c

                2586 0x255cd94

                  2586 kevent

    2586 Thread_3654: com.apple.CFSocket.private

      2586 thread_start

        2586 _pthread_start

          2586 __CFSocketManager

            2586 select$DARWIN_EXTSN

 

Total number in stack (recursive counted multiple, when >=5):

 

Sort by top of stack, same collapsed (when >= 5):

        kevent        5172

        mach_msg_trap        5172

        select$DARWIN_EXTSN        2586

Sample analysis of process 250 written to file /dev/stdout