Your problem is not with your Jepps but with the currency of the practice questions you're using. Not once during my IREX study did I find a practice exam, set of questions etc. that did not have at least one non-existant route designator/SID/STAR etc. on it somewhere. The good news is - when you do your actual IREX, you're guaranteed questions with current data.
I've used Jepps from the get-go with everything IFR - the only hurdle you'll have to overcome (and you might be OK already) is knowing where the AIP information is contained in the Jepp format. For instance, when I first started out, nobody told me that the navaid information is not in the Airport Directory (as in ERSA), but in a separate Radio Aids section - as is other navaid information found in different spots in the AIP book. The only other tiny thing will be in the IREX when you get numerous references to ERC charts, e.g. "refer ERC(L)2", and you'll need to know which Jepp ERC to go for. This is hardly a problem once you know which aerodromes they're talking about.
Once I got my head around where the info was (and Bob Tait is great for this as he gives you Jepp references as well), I never looked back - blitzed the IREX using Jepps without any problems. Good luck.