Computer should be ok although it is very low on memory for running XP, Mach3 will use a bit more resources than Mach2 so it is possible that that may an issue.

Driver test looks fine and I didnt see anything else in the xml that would cause issues.

If you have an extra stick or two of memory try and get it up to at 512Meg and see if it helps, another thing you could try is turning off the toolpath view to see if that helps but unlikely unless the files you are running are large.

What does the frequency and Time in Int say on diagnostics page and also look at the CPU usage and see what it sits at when running some code, Ctrl Alt Del then Performance will get you there.
Hood

I measured the CPU and RAM usage when idle and when running.  I also posted the General Config and Diagnostics page.  I changed a few things in the Gen Conf since I posted the XML's yesterday.  I just turned off high res screens, enhanced pulsing, Plasma Mode (CV), G100 Nurbs (CV), and Home SW. Safety.  After changing all this, it still made no difference; the error is exactly the same.  I will try to get a stick of RAM at lunch and try it this afternoon.

The Time in Int fluctuates between 5.5 and 6.5.  The pulse frequency is steady at 43718.
CPU Usage:
0-12%, Mach3 running, but idle
20-50%, Mach3 running and cutting

Memory Usage:
47104k, Mach3 running, but idle
50244k, Mach3 running and cutting

Frank

Time in Int looks decent and although a bit low the Frequency is at least steady. If I were you I would put te kernel back to 25KHz as you dont need it on 45K so no real reason to use it.
CPU seems fine so hopefully it is just the memory that is the issue.
Hood

Hi, did you get any solution on losing steps?

No, I never did see a resolution to this. I switched back to using mach2 since we are just cutting out simple shapes. I'll be putting mach3 on a new computer and installing all new controls one of these days.
On occasion, we use mach3 to cut some files that mach2 won't cut. They come out ok as long as there aren't a lot of direction changes in the cut file.

Frank,
 when you said this

as long as there aren't a lot of direction changes in the cut file.

It made me look at your xml's again.
In Mach2 you have the Dir pins for your axes set Active Low, in Mach3 however you have them set Active High.
That could well be your problem as if your drives require the active low then you will lose a step on each Dir change.
Hood