The problem is in the lock mechnism, and it usually requires a new lock assembly (~$90). The failure occurs when someone tries to open the door inside while the remote is being used to unlock the door. THis action breaks a tab on a rather whimpy plastic lever inside the latch assembly. Dumb oversite on the part of Volvo and should be covered by them, but it isn't. It is possible to repair the lever, but it is rather time consuming.

This and numerous other problems with our 98 V70 are what I would have expected to have experienced with one of the big 3. Interesting enough, when I use complain about a goofy problem such as this to our Volvo service manager, he would frequently defend Volvo by saying "I worked with GM products for many years, and they have the same problems."

Good luck