When we create a new version of one of our iPhone apps and load it to a device, it shows up as an additional icon instead of replacing/overwriting the old one. Touching the old icon brings up the old version and touching the new icon brings up the new one. This is using ad hoc versions on a debug device -- we have not submitted the update to Apple yet.
We have not had this problem with other apps -- just this one. I suspect the problem involves certificates, OS requirements, or something in the application's default plist.
I can share more information if needed, but I'm not sure which info is relevant. Does this ring any bells with anyone?