Mine has started doing this more now ('05 VTi - 90K km's). I took it to my local Honda dealer who knows me by name (2 Honda's, 1 bought from them) and they did a CVT flush for free. On the invoice they charged me for 1 Ltr of CVT fluid but thought more would have been replaced.
The first time it did it was around 50K but was worse this time, especially when cold.