Are you running firmware-1.3 with all updates? Check what versions you have "apt-cache policy python-gtk2 libgtk2.0-0 mypaint"
~ $ apt-cache policy python-gtk2 libgtk2.0-0 mypaint python-gtk2: Installed: 2.12.1-6maemo10 Candidate: 2.12.1-6maemo10 Version table: *** 2.12.1-6maemo10 0 500 http://repository.maemo.org fremantle-1.3/free Packages 500 http://repository.maemo.org fremantle/free Packages 100 /var/lib/dpkg/status 2.12.1-6maemo9 0 500 http://repository.maemo.org fremantle-1.3/free Packages 500 http://repository.maemo.org fremantle-1.3/free Packages 500 http://repository.maemo.org fremantle/free Packages 2.12.1-6maemo8 0 500 http://repository.maemo.org fremantle-1.3/free Packages 500 http://repository.maemo.org fremantle/free Packages 2.12.1-6maemo7 0 500 http://repository.maemo.org fremantle-1.3/free Packages 500 http://repository.maemo.org fremantle-1.3/free Packages 500 http://repository.maemo.org fremantle/free Packages 2.12.1-6maemo6 0 500 http://repository.maemo.org fremantle/free Packages 2.12.1-6maemo5 0 500 http://repository.maemo.org fremantle/free Packages libgtk2.0-0: Installed: 2:2.14.7-1maemo33+0m5 Candidate: 2:2.14.7-1maemo33+0m5 Version table: *** 2:2.14.7-1maemo33+0m5 0 500 https://downloads.maemo.nokia.com ./ Packages 100 /var/lib/dpkg/status mypaint: Installed: 0.9.1-maemo7 Candidate: 0.9.1-maemo7 Version table: *** 0.9.1-maemo7 0 500 http://repository.maemo.org fremantle/free Packages 100 /var/lib/dpkg/status 0.8.2-2maemo0 0 500 http://repository.maemo.org fremantle-1.3/free Packages 500 http://repository.maemo.org fremantle-1.3/free Packages 0.8.2-1maemo22 0 500 http://repository.maemo.org fremantle-1.3/free Packages 0.8.2-1maemo19 0 500 http://repository.maemo.org fremantle-1.3/free Packages ~ $
I have: Code: python-gtk2: Installed: 2.12.1-6maemo10 libgtk2.0-0: Installed: 2:2.14.7-1maemo33+0m5 mypaint: Installed: 0.9.1-maemo7 And mypaint is working on menu and from command line. It is true that Mypaint needs newer GTK than what we have on N900. You can disable checking of version, but I do not know why you are only one who gets error for this. Remove line 13 from file /opt/mypaint/share/mypaint/gui/main.py You might then get some other error, but again I'm wondering are you only one who gets errors.
python-gtk2: Installed: 2.12.1-6maemo10 libgtk2.0-0: Installed: 2:2.14.7-1maemo33+0m5 mypaint: Installed: 0.9.1-maemo7