As workaround you can add the extension column.
In the list view? How?
Perhaps you could try to change it, if it's not too complicated, I'd like to have more options for list view, already suggested
here.
BTW - since the extension is not displayed sometimes, then it might be considered as a bug - even in Windows Explorer.
Perhaps you could add the new view - combination of details and list view, for example:
[filename1234...exe | 2.55 MB ]
or...
[filename1234...mp3 | 320kbps ]
or...
[filename1234...jpg | 2012-12-05 11-35-42 ]
...So use different option for different extensions, mp3 bitrate for mp3, EXIF date for JPG, size for others.