Actually consider yourself lucky (if your goal is getting 100% in your game) that they didn't register
Each unique stunt has 2 requirements--
1. you have to hit the ramp (obviously)--this triggers the cutscene for it which identifies it to you as a unique stunt.
2. you have to land it correctly--generally each unique stunt has a distance requirement so if it didn't register you were likely not going fast enough-- some others require you to land in a certain place so if you landed--for example, in the alley and you were supposed to land on the roof then it won't register either.
Since the landing comes after hitting the ramp, the game will not give you the unique stunt until you land so as long as you hit the ramp, it will give you the cutscene, whether you've done it or not--this is important since the game does not give you any clue as to which ones you have done and didn't do yet.
You have two options if you want to get all the unique stunts--
1. Get a list of them with directions (print it out)...as you do each one and you get the unique jump message--verify it is credited in your stats...and then mark it off in your directions. If it is not credited in your stats then you may have the missing unique stunt glitch--no worries I'l discuss this at the end.
2. Find them on your own (or at least try)... as you get each one verify that it is credited in your stats. Then in a little notebook, write down each one--describe it as best you can including the direction you were traveling to hit the ramp...don't think you can remember them all--you will question your memory. This is so that if you finally give up and consult a guide...you know which ones you have done--if not you might try to get one again...won't get the message, and think are landing it wrong...or you might go to one you haven't done, not get message and think you have already done it.
By writing them down and/or marking them off a list, you will know which ones you have done.... as you do them...check your stats and when you mark it off or write it down, write down which one it was for you (ie 1/36.....13/36.... 24/36) .....if there is a problem with one of them, you will have some idea which one it is.
Save often, save often, save often....don't reload after you get a jump as you might reload over a jump you did, think you got it but it won't be in your stats...thats another reason to mark them off as (1/36, 2/36...etc) if you end up with 2 jumps with the same number (ie 7/36) you either have the missing unique jump glitch or you may have reloaded over your jump.
Now...the missing jumps glitch....some debate whether this actually exist...if you number your jumps as I described above and are careful not to reload over your game then you should not have a problem...but if the glitch does exist and you are absolutely sure you did one, got the "unique" message and it does not register in your stats----note which jump it is and come back to it...I'm told this works so try this....power down your game console and remove the memory card and then restart it...let the game start from the begining and click through the beginning cutscenes...when the game finally starts...pause it....insert your memory card and reload your saved game...now tyr to do whichever one that did not register in your stats...you should be able to get it now.
You can ignore my advice but nearly everyone who does will end up trying to figure out which ones they have left when they are down to 1 or 2 left....I've seen it before.
Also, most of the jumps are best done on a PCJ--others will register with any fast car but the PCJ is the fastest vehicle so it should give you the distance...also, you can duck down on the bike to get a little bit more speed as you approach the ramp(s)
I know this is kind of tedious but you will thank me. I'm playing GTA3 for the first time now and am not using any guides...I've been writing down each rampage, unique jump, and hidden package...so I don't run into the same problem that I had on VC.
I'm at 65/100 packages, 8/20 rampages, and 13/20 unique jumps...all written down.
Spuds
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