It's totaly exaptable temmperature!
u can use RIVATUNER to control cards fan speed manualy,
mine idles at 50C on 40% fan speed, 40-43C on 50%, while gaming I set to 70% it keeps 55C...
so try this program to control manualy gpu's fan speed!
for AMD- get better cooler if u not happy, but if u not doing Overclock than it's ok!