I finally solved this problem! Amplitube 5 is now working in the latest Garageband, here is how to do it. Note before you try all the steps, skip to step 5 and do that and the subsequent steps first as this may be enough to solve the problem, if not, then start with step 1
1) First browse to Go > Computer > Macintosh HD > Library > Audio > Plug-ins > Components
2) Delete the AmpliTube 5.component
3) Next delete the Amplitube 5 application and choose to reinstall it with the IK Product Manager App
4) Once reinstalled verify that the new version of the AmpliTube 5.component exists in the directory where we previously deleted it
5) Now open Garageband and under preferences make sure Audio/Midi > Enable Audio Units is selected
6) Next under Settings > General make sure that Open plug-ins by in Control view by default is deselected
7) Create a new project, add a guitar, go to the plug-ins as usual and select Amp Designer > Audio Units > IK Multimedia > Amplitube 5
Rock on!!!!!!!!!!!!
