When I use the "Load FPGA" command in iMPACT 5.1i with Service Pack 1, I cannot configure the FPGA with the PROM directly after programming. I must toggle power before the FPGA will successfully load.
If I watch INIT, I see that it toggles in this situation.
The problem occurs when iMPACT uses concurrent mode, which causes it to put another CONLD instruction after the CONFIG instruction. This can been seen if an SVF file is created for the PROM.
To work around this issue, program the PROM without concurrent mode by going to Edit -> Preferences -> and de-selecting "Concurrent" mode.