I had similar problems with the preacher curl bar. I have two recommendations.
1. Try doing straight bar curls with perfect form. You don't want your elbows to come forward at all. If your bicep relaxes at the top then you've gone too far. You should be able to tell this point because you will have a hard contraction at the top, if you go to far your bicep will relax right after the contraction (not good). It will be a lot harder than normal and you might feel like a pussy only curling 60-70lbs at first but you will be amazed at the eventual results.
2. Stretching is my second recommendation. Your problem which is similar to shin splints may possibly be solved with some simple stretching. Many runners get shin splints from a lack of proper stretching. I had shin splints and those forearm splints as well. I incorporated some stretching techniques after a light warm up, during and post workout. This alleveated the pain completely in a matter of weeks. I won't get into how I stretched my legs out since it is obsolete. There are a couple good stretches for your arms you may be neglecting. You want to stretch your triceps, shoulders and most important your forearms. Position your arm straight in front of you with your fingers pointed up, with your other hand bend your fingers on the straight arm back towards you, you should feel your forearm being stretched on the bottom side. Next, point your fingers down, with your other hand bend your wrist towards you, you should feel your forearm being stretched on the top side. Vice versa for the other arm. Hopefully you know how to stretch your shoulders and triceps so I won't get into that. This is probably the best advice given here, many people over look stretching when it comes to exercise and try to cover up pain with pain killers. It only lasts so long! If you haven't been stretching, then start and you will be amazed at the results, you will lift heavier without pain. Don't overdo you stretching either I don't want to see you overstretch and hurt yourself. Hope this helps.
speedy
Try to keep it real and don't be stupid!