hmm, could be that /usr/local/sbin is not in your path, edit the vboost.sh file to point to /usr/local/sbin/i2cset
Remember to run it as root, or download the new deb (same link which checks for kernel and root).

Yes, syslog is /var/log/syslog
I suggest echo "" > /var/log/syslog every once in a while to clear it as it can get very large and fill your /