I discovered a bug in the ImageBrowser today while testing.
The problem occurs when uploading two different files in quick succession. I click the Upload button in the ImageBrowser, select a file, then quickly click the Upload button again, and select a different file. After both requests to the Upload URL complete, the ImageBrowser shows the two new files, but they both have the filename of the first file.
I also tested this on the Kendo demo for the ImageBrowser at http://demos.telerik.com/kendo-ui/editor/imagebrowser , and it does the same thing.
Here are some screenshots to hopefully help show what's going on.