Version:           2.3.1 (using KDE 4.4.5) 
OS:                Linux

Since Amarok 2.x library only updates itself when a file is added or removed from the library, I need to rescan my entire library if I make changes in the id3 tags of songs without removing them from my library first (which is not a problem). However, when I re-scan my collection from the Configure Amarok dialog (Settings -> Configure Amarok) the library view goes awry. Artists lose albums, songs duplicate, pointers get lost sometimes (cannot play a song if it is visible). Luckily this is fixed by a Quit & Relaunch of Amarok but, that shouldn't happen in the first place. BTW, I use Kid3 for ID3 tags since it provides a more detailed view and gives better control over tags and details.

Reproducible: Always

Steps to Reproduce:
1- Launch Amarok.
2- For joy, start playing some of your favorite tracks.
3- Notice a bad song name or missing tags (can be any song, playing or not, in playlist or not).
4- Launch your external ID3 editor (In my case it's Kid3) and correct the tags and save the file. Do NOT rename the file (in order to don't wake the Amarok :) ).
5- Find out that Amarok didn't pick up the changes. Update collection doesn't work too since there's no filename change.
6- Open Settings -> Configure Amarok; go to Collection and order a complete re-scan (Fully rescan entire collection).

Actual Results:  
Your collection is scanned but some library entries (incl. you have not touched in any way) goes awry. Some artists are now empty, some of them duplicated, some songs are missing etc.

Restart fixes the display issue and brings back the library back but it's freaky.

Expected Results:  
Your collection is scanned and the changed songs are in their proper places with their new shiny tags, organized neatly.

OS: Linux (i686) release 2.6.32-5-686-bigmem
Compiler: cc