iphone - Xcode 5 shows the same device twice

Question

Ever since my team switched from Xcode 4 to 5, this weird bug shows up, that:

When we connect the iPhone/iPod touch to the macs, the device will be shown as two devices as deployment candidate. Both have the same device name correctly displayed but if we run our app on the 1st one, sometimes a segue will cause a crash whereas the same segue will work fine on the 2nd one.

This issue occurs on all of our devices on different macs: iPod Touch 5, iPhone 4s, iPhone 5 with iOS 6 and 7

So my questions are, why are there 2 of the same device, and further, how do I fix it?

Answer 1

as @Petesh states, this is due to adding the 6.1 SDK to xCode 5. Additionally, one of the devices will run with iOS 6.1 visual styles while the other will run with 7.0 styles. Sadly you can't tell the difference which will run with the 6.1 styles and which will run with the 7.0 styles.