I check the Telecom Broadband meter on a regular basis (usually once a day) and I check and note the figures. I also run rrdtool on one of my machines so that I can check telecom's numbers against what my cisco router says...

Three days ago the meter was 'unavailable' - I assume they were playing with their system?

Two days ago I had used just shy of 25Gb

Yesterday it said 28.6gb - this gelled with the modem, which at the same time reported 28.2gb. I was unconcerned with the minor difference.

Today I log in to telecom and the number has jumped up to 35gb. I look at downloads for yesterday and it says we used 1.7Gb... so i'm thinking 28.6gb + 1.7gb = 35gb?... not likely

I looked through the figures from yesterdays check, and then compared them against what the usage meter says for today.

Strange, all of the UPLOAD numbers are identical... but some of the download numbers are waaaay different

Take the 15th of April - 2 weeks ago... yesterday the Telecom usage meter said 5.2gb. It has said that since the 16th. Today that number has jumped to 7.8gb.

The 16th shows a similar discrepancy - since the 17th it has said 5.1gb and now says 6.7gb, 

This morning (around 8:10am) the usage meter had said 4.3gb was downloaded on the 23rd... now at 3pm it says 5.2gb.

The service has been in place for almost a year and most months the amount my modem reports via rrdtool is within 1gb of the telecom usage meter (thats 1gb over 60-80gb of usage... so within say 1.5% of agreement, not a big statistical difference) but whatever has happened this month/ today with their usage tool has already put the difference between the two into double digits... 

WTF???