gtkmm 2.18.2 is needed as 2.18.1 broke API and ABI. See the following commit: http://git.gnome.org/cgit/gtkmm/commit/?id=bf601e53904ff543309ae597f32a928776b6d3e7
Hubert, do you know if any gtkmm-using applications are hit by this ABI change in Fedora 12 ? 2.18.2 is built and ready, but not currently tagged for F-12 final.
Gnote is one of them. But given that is an API and ABI *breakage*, acknowledged and fixed by upstream, it doesn't matter if there is or not an app in Fedora that is impacted. The platform is broken.
No question the update is needed, but I need to know the impact of it this late in the process. F-12 is frozen and it's probably too late to request a tag override before F-12 is released. Gnote now seems reasonably happy in F-12 with gtkmm 2.18.1, even though it was compiled against 2.16.0. After installing 2.18.2, gnote seems unaffected. I guess if it was compiled against 2.16.0, it's guaranteed to work with 2.18.2 since the ABI breakage is fixed. I'll file a rel-eng ticket for the tag override, and we'll see how that goes.
Try building Gnote (either the 0.6.2 package or git master) on F12/Rawhide with Gtkmm 2.18.1 and tell me how it is working out for you. The fact that it hasn't been rebuilt in a while isn't foreign to the fact that it seems to work.
gtkmm24-2.18.2-1.fc12 has been submitted as an update for Fedora 12. http://admin.fedoraproject.org/updates/gtkmm24-2.18.2-1.fc12
gtkmm24-2.18.2-1.fc12 has been pushed to the Fedora 12 stable repository. If problems still persist, please make note of it in this bug report.