update-apt-xapi takes lot of cpu usage

I've had the same situation described here http://naveenubuntu.blogspot.com/2011/10/ubuntu-update-apt-xapi-takes-lot-of-cpu.html. Every time I tried to use anything, update process takes all available cpu time.

I solved the problem by following the indications mentioned in the above post (actually, what solved the problem was to kill -9 the process and then chmod it).