I tried it myself also a few minutes ago, on an old Droid Eris/HTC Hero (IIRC) running CM7, Android 2.3.2. It does do an odd double-loading thing, but it doesn't show the alert.

Also, damn this thing is slow and tiny compared to my current phone.

Tried again with a Galaxy Nexus on 4.3. Sure enough, it duplicates fine on the stock browser, and works correctly in Chrome.