Normal Programming Will Resume As Soon As Possible If you could just pass me a napkin... I'll try to wipe a little of this humble pie from my chin. The portion I have had to eat this week was particularly generous.

It was around this time last week that I was happily spouting off about my son and his 'prolific' TV-watching habits. Oh how clever I was, laughing in the face of common sense and extensive research which suggests that responsible parents limit their kids' TV viewing to an hour a day. Recently, whenever I have happened across such research I have tried to ignore my maternal red flag, my guilty little secret. I knew that Levi's viewing (especially in the last nine months during our renovations) exceeded this recommended limit, but I was always too scared to crunch the numbers and find out by exactly how much.

I have usually found a way to justify Levi's viewing habits - which is what I was doing last week. Sometimes I have even taken to a higher ground in my attempts to placate the inner beast of mother-guilt. Using the argument of respected academic and social commentator Catherine Lumby, I have been known to shout down the voice of reason. Lumby (with Duncan Fine) wrote a book in 2006 called Why TV Is Good For Kids which suggested that, "TV, pop culture, toys and technology will not make your children a) fat, b) violent, or c) stupid". When a clever (though childless) friend told me of Lumby's ideas I gobbled them up. Being a fan of popular culture myself, it was an argument that resonated with me immediately. I stopped worrying about Levi and TV and pretty much gave him carte blanche over the remote.

What I didn't factor in was Levi's adoration of the medium. His sister seems to have an inbuilt TV-watching self-regulator and she usually casts little more than a cursory glance at the screen before she takes herself outside to hang from the monkey bars, play with our rabbit, ride her bike or just generally daydream in the backyard. Levi rarely does any of these things without prompting. Again I would trick myself by saying that he runs around all day at school with his mates, has the build of a whippet and is as clever as can be. He also matches his passion for television with a passion for books. Surely that means everything is okay? But last week - when I did my canteen duty - Levi's teacher came in at lunchtime to collect his salad and pulled me aside for a chat. "What's wrong?" I laughed, wondering if I hadn't cut his carrot sticks properly, safe in the knowledge that my boy was not the problem. Mr Croak told me (in the nicest possible way) that Levi has not been completing his work in class. I was aghast. Apparently, for the last month or so Levi has been complaining of feeling sick when he is asked to do his work. Unless his teacher sits with him the work does not get done. Oh. My. God. It's that parental moment that you just don't want to have. I asked if Levi was actually struggling with the work but Mr Croak didn't think that was the problem. As I served up endless water ice-blocks I wondered what was wrong. I knew Levi was not actually ill - his energy levels at play time attest to that, and his teacher agreed. I also regularly ask my kids if they are having problems at school or with other kids - Levi's answer is always an emphatic 'no'. He loves school and on weekends constantly asks when it will be Monday - so desperate is he to get back there.

And then I felt I had hit on an answer, plain and simple - he watches too much TV. A few weeks ago when I wrote about our morning routine a kind reader suggested I turn the TV off until after the kids are dressed. It was a fabulous piece of advice and one that I immediately recognised as sensible and true. But I tucked it away in my little mothering file and told myself everything was just fine. However, everything, it seems, isn't just fine. I have to acknowledge that, now that the renovations over and our backyard is no longer a construction zone, there are no more excuses for spending our downtime huddled around a screen, trying to forget our woes. Levi and I had to have 'A Talk'.

I took him to the park that afternoon. As the little guy sobbed - thinking he was in trouble - I told him that Mummy and Daddy were concerned that the TV and computer were taking all his 'brain energy' and that was why he couldn't do his work at school. I told him that I would have to ban him from screen-time until I heard that his work had improved. My son nodded his head. He got it - and I knew he got it. He was prepared to take his medicine, which to him feels like - but isn't really meant to be - a punishment.

I have since found out that Luke also took Levi aside and chatted about the importance of education. Luke's argument was probably better than mine. He told Levi that some people make a living by creating TV shows and computer games. "They get to spend all day on the computer and watching TV," he said. But, Luke insisted, to get a job like that you have to do well at school. Levi's eyes lit up in disbelief at this promise of an adult world so fantastical. "Really, Daddy?" he asked. "Well now I am going to work really hard at school." Makes sense to me.

Do you limit your kids' TV viewing? Have you ever had to eat humble pie when a parenting approach went wrong?