I have a 07 XLS (OEM NAV and RF system). My previous phone, a HTC Incredible, paired flawlessly. I never had any issues with it. Upgraded to a iPhone 4...never stayed paired for more than a day. I finally got tired of pairing daily and started using a BT headset. It sucks knowing a have BT built in, but can't use it reliably.

 

I can't offer a solution, but thanks for the thread. I was going to get an Iphone 4s, but will stay in the Motorola family. My Droid works flawlessly (now). My next phone willl be a Droid Razor

 

I was having the same issue with my '07 Outlander XLS not staying synched to my new Iphone 4S. Here's what I did which seems to have resolved the issue, though not sure which, if either, corrected it: 1) use a different pairing code when you sync the phone than your unlock code on your phone. 2) set the Iphone to priority other than 1 -- I used 2. Prior to doing the above, the car and phone never stayed synched after ignition off. But now it has stayed connected 3 days in a row. Hope it works for you guys.

 

OMG....I can't believe this worked for me! It's been 2 days and my iphone continues to work with my Bluetooth! I used pairing code 2222 instead 0000 and I made it priority # 2 instead of # 1 and now it works permanently! Thanks for your help!

 

This may not be the case for everyone, but...

I've noticed that if I turn my iphone 4 to silent mode with the little switch on the side of the phone and forget to turn it back to "normal," the system won't pair the phone. If i remember (which I normally don't) to turn it back to normal before I get into the car and start the engine - it works fine.....

so I agree with a previous poster...sounds like some weird issue with the iOS

 

i had same problem
replaced bluetooth module under mmcs unit to latest version firmware version