You can use the nightly with the compiler bundled with C::B 16.01 (TDM 5.1) without uninstalling 16.01.
Yes, I thought so, obviously.
Just to repeat, I guess it would be good to correct the 32 bundle of Code:Blocks in the download page, to include the gcc 32 bits in it. This is currently both not working and misleading, and I suspect this is a mistake.
Cheers, & thanks again for your help.
Eric.