Strange problem after changing reset vector

Hi again,

I think I found the bug myself.

I rebuilt the Quartus project with some changes and the situation was even worse: I couldn't load the Nios program because I got and "Invalid system ID" error; moreover the fpga outputs connected to PIOs behaved in strange ways just after configuration.

Then, I erased the epcs device with the programmer and everything was perfect again.

So, I think the problem was with data from previous configurations stored on epcs. When I switched Nios mode from flash to epcs, probably Nios tried to boot load from this invalid data, leading to instable behaviour or corrupting sopc components init status.

Can anyone confirm if this is a valid explanation?

Thank you

Cris