yes, i did. I even installed simplyMepis 6 on the same system to see if only fedora core has this problem. I used amarok under mepis and it behaved similarly. here is the part of top output:
top - 12:30:45 up 24 min, 1 user, load average: 0.64, 0.51, 0.47
Tasks: 109 total, 1 running, 108 sleeping, 0 stopped, 0 zombie
Cpu(s): 5.0% us, 2.7% sy, 0.0% ni, 92.0% id, 0.0% wa, 0.0% hi, 0.3% si
Mem: 506356k total, 499504k used, 6852k free, 13896k buffers
Swap: 1140604k total, 0k used, 1140604k free, 276880k cached
The strange thing is that when i use my ubutnu laptop with 1gb ram, things are running fine.