We had that problem a few years ago too, only difference was the floor was put down just a few months before. I reckon your problem is with the expansion space under the room's skirting board. It won't cost you much (outside of a bit of your own labour) to investigate. All you have to do is remove the skirting board for a few minutes. Do it properly and you can put it back within minutes.
If there is no expansion space, you need one and depending on what way the tongue-n-groove is placed you could have a problem.
But, your floor is 13 years old. It owes you nothing. If you have to get a new floor it would be worth enquiring about the newer underlay which is heat efficient and will repay your costs in time.