Under Samp problem on USRP N210

Hi all

While running USRP N210 on 25M/S, on core i7 its ok but on core i3 error
comes UUUUUU. i think its because of System sending low samples on port
then USRPreceived. the main problem is when usrp isrunning asUnder
sampledthe power on centeral frequency increased for a short spain of
time"Spike comes 6dbmmore thenoforiginalsignal level". Dose any one have
idea about that?
Regards
Muhammad Junaid