Seetting importance to High:
1. Has a severe impact on a small portion of Ubuntu users (estimated)
2. Makes a default Ubuntu installation generally unusable for some users
* For example, if the system fails to boot, or X fails to start, on a certain make and model of computer
3. Has a moderate impact on a large portion of Ubuntu users (estimated)
Seetting importance to High:
1. Has a severe impact on a small portion of Ubuntu users (estimated)
2. Makes a default Ubuntu installation generally unusable for some users
* For example, if the system fails to boot, or X fails to start, on a certain make and model of computer
3. Has a moderate impact on a large portion of Ubuntu users (estimated)
I believe #2 breaks further updates/synaptic too.