Pointer Problem with E1505 Inspiron Notebook

My pointer keeps getting stuck midscreen.  I worked with a technician on the Dell support chat line and he diagnosed my problem as a faulty palm rest.  He told me to call the parts department and order a palm rest assemble and gave me this number, NC929, as the replacement part to be ordered.  He said it was a kit.  Unfortunately what I got was a new keyboard.

 

Now I am confused.  Did he give me the wrong part number or did he actually intend for me to replace the keyboard.  

 

The problem that I am trying to correct is this:

My pointer will suddenly stop functioning.  It freezes on the screen and it won't move with finger pressure on the mouse pad.  It will however, move if I hold down ANY key on the keyboard and then direct it with my finger on the pad.  When I lift off the key...it stops working again.  It also fails when I am in the safe mode so we have pretty much determined it is not software related.  

 

I've been told this is caused by a faulty palm rest.  How??  Do they mean....mouse PAD assembly AND Palmrest.  How does the palm rest interact with the mouse pad surface.   Are they thinking there is a loose connection in the palmrest cable assembly.

 

Last but not least.........if it is the palm rest can anyone provide me with the correct part number.  Right now it is working again but I still have brief periods where it stops working. 

 

Thanks in advance for any help or guidance you can provide.................tricky