The bad news: I had three cables die out, all within about a month of being installed. The old version cable, which can be seen here (http://youtu.be/TSR3rXSwFao?t=1m25s) just never worked for me and fell apart shockingly fast.
The good news: Beyerdynamic have a new cable that has held up (at least for over two months so far), and they've been super helpful in getting my T5Ps re-cabeled in-warranty, despite me living half a world away.
The better news: everything else about this headphone is simply fantastic, and now that the cable issue has been solved I don't have a single complaint.
I've just had the same thing happen to me as well.
Had mine for 6 months and have sparsely used them (at home only).
This new cable you talk of - is the entire cable new or just the termination??