Strange, it loads fine when I use your xml so there is nothing wrong with it either. Maybe reinstalling Mach over the top of itself would cure it. One thing, what size computer do you have? If the graphics or CPU are lowish then try disableing the toolpath from General config and see if it loads.
Hood

It's a 2.2 Ghz HP w/ windows xp 2002 version. i followed the Mach requirements for Ram. I will try reinstalling Mach-- anything i should be aware of in doing that?

Not really, just run it again and it should install over the top of itself. First however just disable the toolpath, you will find a button on the Diagnostics page right above the reset that will turn it off, I was thinking it was in General Config as well but maybe not.
 Oh and if you reinstall Mach then probably an idea to re-download it just in case the one you have is corrupt.
Hood

if i disable the toolpath from config and it loads, do i then un-disable the toolpath to run the file?

No, its just you wont have a toolpath view. What that will show is your CPU or more likely your graphics card is getting bogged down trying to load the toolpath.
Hood

disabling didn't work -- the file shows up in the FILE line but not in the green Gcode box

It's kind of a simple file -- just a rectangle -- so the graphics card shouldn't be overloaded. I will reinstall Mach.
thanx again, bob

that is a weird one indeed, never seen that happen before.
Hood

OK, now I'm really confused. since i played w/ the soft limits earlier, i thought i'd jog to the middle of the table just to see if maybe that had something to do w/ it, and i've apparently got that screwed up. the axes will only move in one direction and when i move in that direction and then try to move back, it will move about 1/2 inch and then stop -- that is, the axis will stop but the stepper will sound like it's being stressed. 1/2 inch is what i have the slow down set at. the table is x44 by y24 by z7, so I set the soft maxes at x43, y23, and z6, with the soft mins set at 0. the checks at the left under the heading Reversed are all red, the checks under the heading Home Neg are all red, and the checks under the Auto Zero are all green. I have 000Home set at the upper left corner if you are standing at the open end of the table where you would put the material in. is that all wrong?

it gets weirder -- see above