only unreliable, then total failure

I bought the piece in December 2011
Basically, the adapter cable worked.
Following considered, but it has cost me time and nerves! Why? There was sometimes unreliable in operation of the connected monitor (flickering, not switch, "block noise"). The error occurred only occasionally, so I poured myself a decent misdiagnosis due to lack of time. Just looking Mac restart abstecke cable and reconnect, then it went again. The adapter cable was located in the signal path of Mac dock DVI cable monitor. All it could have been. The adapter cable I had the passage of time is no longer on the screen. Last week, now only black screen. Ignore no longer went!
Night use, which I suspected fault everywhere except in the short piece of cable. Anger !!! Tested the next morning as a last resort adapter cable cross-comparison. It appeared to be defective. Ordered original Apple adapter and built-relaxation! No new monitor or Mac was required, only this failed .... Cable had stolen my last nerve. Immediately I buy only original Apple!