In NetMRI you can see when those occurred by clicking the link for that interface instance in the issue details. In the window which eventually displays (after WAY too long), in the Performance History table at the bottom, change the view to Counts. Then select Hide/Show Columns and enable "Changes". You can then see how many interface changes occurred during each polling interval. (I enable quite a number of other counts/columns and make that my default view.)
In the IOS device itself, "show interface" will display carrier changes since reboot or clearing of counters, but that doesn't increment for logical interfaces like tunnels or PVCs.
HTH,
- Marty