Programming ERROR with EPM900

[Caleno]

Hi, I am trying to program the LPC936 with the EPM900 via ICP. The Micro is in the application already soldered. It was working fine as far as programming, but I have changed PCs and now I am getting an error message when I try to download the program. This is what I get:

*** LPC900 EPM Loader V1.01
*** LPC900 EPM Programmer V1.20
Flash Erase Done: 3 sectors erased.
***ERROR: Flash Write Failed at Sector 3.  

What could be happening here? I cannot go back to my previous PC where it was working fine.  
Pins that I am using on the chip are P0.4, P0.5, VSS, VDD, P1.5.

Thanks

Caleno

[Caleno]

Thanks guys I found the error. Since my program increased in size, I had to increase the number of sectors to be errased. I had to include sector 3.
thanks

Juan H.