Help - (sigh) Can't seem to let this go...

Ok, so I'm 1) feeling very, very slighted and 2) sorry for myself. My agency is holding a two-day inservice - for RN's only () for training in our specialty. Why RN's only? Don't know. My supervisor says she doesn't know why LPN's weren't invited.... (Gee, do you think you could find out???? Of course not.) It has nothing to do with case management, it is specific training for what we do every day. Yet again, I feel slighted. I do the exact same job - every day - alongside an RN. I am expected to do the same tasks and carry the same case load and responsibilities - of course for less money. I accept that. But gee, I'd like that extra training too! Who will be out covering the RN's that day? Guess who?? What gets me is I have obtained specialty certification in this field that 99.9% of the RN's haven't, included the RN I work with. This is starting to really affect my attitude (and feelings!)
Thanks for letting me vent. Any suggestions on what I could do or just suck it up and deal with it?
Thanks,
mc3