Is it very common to put a jockey (retained) on your horse then when the race comes up its a totally different jockey riding it? It's happening to me a lot lately

are you actually physically nominating him for the ride when you nominate your horse for a race?

Are you entering horses at different meetings on the same day? if you've selected to auto put the jockey on then this can get messed up as he will ride the latest entry. Or even if you've clicked a jockey to ride at 2 different meetings one horse would be left without a jock so the computer will randomly select one.

To be honest I don't think it matters a great deal anyway. I've had 4/5 horses in the same G1 races before with the likes of Hughes, Moore, Dettori ect up and its been the outsider ridden by a random pick (the likes of Fahy, Ffrench ect) that has won.

i autopick him but i realize you could be right there about double booking....better keep my eyes open a bit wider then thanks

Yes if you have it on auto pick the retainer will always ride the entry you make last.