Sediment is normal in "older" wines, it can simply be small particles of yeast that was not caught by the filtration.
As time goes by, the particles will stick together and fall to the bottom of the bottles.
Most of the time it will not affect the (taste and flavor) quality of the wine, but will show up more when not being cautious when pouring the wine.
Just be more careful when pouring wine; you can also use a decanter.
Slowly pour the wine into the decanter from the bottle to let the sediment get caught in the shoulder of the bottle.
If there are sediments, you will loose maybe 1 teaspoon of wine; but you will be assured that the wine in the decanter will be free of sediment and when pouring for friends at the table there will not be any sediment in the glasses.