I have two questions about bicep training. I am a 19 year old beginner who has trained before on and off but really now have decided to get dedicated and really stick it out for the long haul. My bicep workout is simple but "seems" to give me a good workout. With freeweights:

Seated Curl: 3x9

Seated Hammer Curl: 3x9

I have been training now again for 3 weeks and been dedicated to being in the gym everyday to do my routine, today i worked my biceps for the 3rd time since i started up again and i've had several problems. My first problem is that i seem to be stuck at one weight. I started back up with nothing too heavy 15 pounds on either hand and feel like i have been "stuck" at this weight. I've tried completely starting my routine with a higher weight and trying to force my way through it but finding after one set i cant even get the weight up again. Today i tried warming up with the lower weight and moving back to the higher weight only to encounter the same problem, i could -not- get the weight up. I was wondering if this is something to be worried about or is this normal? Any suggestions into overcoming this problem would be greatly appreciated.

My second problem is while i am stuck on this one weight i do see my biceps devloping, the only problem is it seems like the only part of my bicep really developing is the lower portion of my bicep. When flexed during/after workout it seems the peak of my bicep is slightly lower than the middle. I have made a point to concentrate on form first over weight and have run into this problem also. Seeing how i am not an experienced weight lifter i am somewhat discouraged/confused into approaches i should take to solve these problems, any insight would be greatly appreciated.

thanks in advance,