.xsession-errors query

[jamie@fastmail.net (jamie)]

Hi

I wanted to ask a question about the file ".xsession-errors", namely its
contents. 

Inside this file in my home directory is see this:

X Error: BadWindow (invalid Window parameter) 3
  Major opcode:  19
    Minor opcode:  0
      Resource id:  0x2200008
      X Error: BadWindow (invalid Window parameter) 3
        Major opcode:  19
	  Minor opcode:  0
	    Resource id:  0x1800002
	    X Error: BadWindow (invalid Window parameter) 3
	      Major opcode:  19
	        Minor opcode:  0
		  Resource id:  0x1c00008
		  X Error: BadWindow (invalid Window parameter) 3
		    Major opcode:  20
		      Minor opcode:  0
		        Resource id:  0x1c00008

I don't know what this means and if it's something i should be worried
about. I wondered if anyone could explain it to me and advise if there's
anything i need to do to stop these error messages. 

Many thanks. 

Jamie