Just a note, straight ADB push will not work. Need to reboot clockwork recovery, then use the partitions menu to mount /system. After that, adb push, then chmod as 755. After that, I highly suggest copying the bin and xbin folders from the cm 188.8.131.52 update.zip to your sdcard then running:
/system/xbin/busybox cp -i /sdcard/bin/* /system/bin/
The -i prompts for overwrite. Best to deny any overwrites, being an updated system and all.
Do the same with xbin, and you should be able to busybox like normal.