Mine has been running stable at 1500 all week (230GHS), I upgraded the firmware to 20131229:
http://downloads.canaan-creative.com/software/avalon/20131229/openwrt-ar71xx-generic-tl-wr703n-v1-squashfs-sysupgrade.bin
Updates the cgminer version to 3.9, I didn't really notice anything different but perhaps it would help people with problems.