My GPS shows me in a position 100 miles away, how do I sort it?

Question

According to the maps on my phone, I'm apparently over a 100 miles away from my current position. I've resynced it a couple of times, switch airplane mode off and on and now at a dead end. Has anyone got an idea of how to fix it?

Answer 1

This is caused by using the same iCloud account on both phones.  When you do this any data you sync with the shared iCloud account such as contacts is merged and will appear on all devices connected to the account.  To fix this you both need to have separate iCloud accounts (you can continue to share the same Apple ID for purchasing from the iTunes and app stores). 
Decide which iPhone will be keeping the current iCloud account.  On the one that will be changing accounts, if you have any photos in photo stream that are not in your camera roll or backed up somewhere else save these to your camera roll by opening the photo stream album in the thumbnail view, tapping Edit, then tap all the photos you want to save, tap Share and tap Save to Camera Roll. 
Once this is done, go to Settings>iCloud, scroll to the bottom and tap Delete Account.  (This will only delete the account from this phone, not from iCloud.  The phone that will be keeping the account will not be effected by this.)  When prompted about what to do with the iCloud data, be sure to select Keep On My iPhone.  Next, set up a new iCloud account using a different Apple ID (if you don't have one, tap Get a Free Apple ID at the bottom).  Then turn iCloud data syncing for contacts, etc. back to On, and when prompted about merging with iCloud, choose Merge.  This will upload the data to the new account.
Finally, to un-merge the data you will then have to go to icloud.com on your computer and sign into each iCloud account separately and manually delete the data you don't want (such as deleting your father's contacts from your account, and vice versa).