Built the iso with nLite from an xpsp2 disc and the sp3 download from microsoft. The winxpsp2 disc runs a virtual machine in virtualbox without any hiccups. But the sp3 slipstream onto this xpsp2 disc throws error messages in virtualbox. With the same settings, just seconds later, in the same virtual machine, with the winxpsp2 disc will run without any problems. My conclusions: (1.) the winxp2 disc is OK, (2.) the virtual machine and the virtual machine settings are OK, (3.) something is wrong with the nLite setup, (4.) don't know about the sp3 file, didn't do a checksum.
But how to find possible errors in the nLite process when no error messages are given in the integration process, and the process goes smoothly with a final message "integrated install completed successfully"? Have attached screenshots. Notice in the last screenshot that the iso produced by nLite is 6,419,990.656bytes. Is this the right size?