| This is what happened to my bike last year, it dropped one of the valves out of the collet at high revs and the cylinder stopped running.
The garage I took it to took ages to look at it, when they did they sent the cylinder head to have the valve re-pressed into place again. When it came back the valve dropped straight back in again, so they had to replace the whole cylinder head in the end. Luckily it was all done on warranty and I got a free major service cos it all took so long.
If your bike isn't still in warranty I'd write to Ducati UK requesting them to cover it by warranty because they told me this shouldn't happen. Also, if you need a new cyclinder head it costs £1000 new I was told!
Thats if your problem is the same as what I had anyway.... | 
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