Error Changing Mobile Messaging Monitoring Options

I have tried with no success to change the monitoring status of a number listed on my daughters 'Mobile Friend list' from 'Unmonitored' to 'Monitored' please advise.

When i select a number from the list and choose the radio button 'Monitored' and click on save i only get "Sorry, An error has occurred on the server/ Please, try your request again later" this has gone for well over a week (at least that is how long i have tried) and I would like some advise to correct this problem.

Thanks,

Jeff