I'm not sure but the root of your problem might be the amule version and wxWidgets combination you are using. I have heard that:
amule development branch + wxWidgets 3.0 = OK
amule 2.3.1 + wxWidgets 3.0 = Problems
amule 2.3.1 + wxWidgets 2.8 = OK
Many distros are upgrading to wxWidgets 3.0 so this might lead to people running into issues. I use Gentoo Linux and I had to go to manually take it down to wxWidgets 2.8 to get into to run properly with amule 2.3.1.