>I had a similar error that refered to memory at 0x00000000. It appeared whenever I was low on resources (like when I have Excel running in the background).
>
>I figured it had something to do with virtual memory and that my swap file may have had some corruption. Try turning off virtual memory and make sure that the swap file is deleted, then turn it back on.
>
>I figured that it couldn't hurt and I haven't seen the problem since. (I had also freed-up some space to allow for a larger swap file, so that may help as well.)
>
>I hope this helps.
>
>>I am getting the following error today. It started just before noon.
>
>>VFP6.EXE - Application Error
>>The instruction at ox77f1d493 referenced at "0x00000000". The memory could not be "written". Click on OK to terminate the application. Click on Cancel to debug the application.
>

Something tried to read or write to a NULL POINTER. This is an error in binary code; it's doubtful that a consistent process inside the interpretive environment can repeatedly and directly cause this. It's likely to be sloppy programmer time at MS, or one of the third party pieces that your VFP app talks to directly - someone allocated memory, got a null pointer back, didn't trap the error and just used the returned null. AKA Sloppy C programmer trick

-- Sloppy C Programmer