Copy and paste is much more reliable for this sort of thing, as it allows easy isolation of any typos actually in the output (indicating a typo in the repository list, naturally).

But your actual problem appears to be twofold. First, you're trying to use the SDK repo on the device; this is not recommended and, when sufficient caution is not exercised, it's quite easy to wind up with a non-bootable device. Maybe you know quite well what you're doing, but if not, consider yourself scared and go back to repos meant for the device.

Second, that's no longer there; now http://repository.maemo.org/dists/diablo/ has two subdirectories, sdk/ and tools/, where the sdk/ contains the same tree that used to start from, e.g., http://repository.maemo.org/dists/chinook/; the tools, by the way, is developer stuff that's safe to install on the device.

I currently have the tools repo enabled for my device, with distribution 'diablo/tools'; similarly for the sdk, although I don't have that configured (in this boot image).

Edit: BTW, I'm no Debian wiz, and freely confess my ignorance of how repos are supposed to be set up. Using a slash in the distribution name looks like a clumsy workaround; if this is wrong, and someone knows the right way to set up those repos, enlightenment is welcome. But what I've got works for me.