Mods - if this isn't the place, please feel free to move it...

I have two of the Avent Magic Cups for DD. Avent claims they are no spill. Hwever mine are always leaking!!! Does anyone else have this issue? I've checked to ensure the lid isn't screwed on too tightly and have also checked the valve is assembled correctly. I even had it checked by someone at the Pregnancy, Baby, Child Expo a few weeks ago. I've emailed them and am waiting a reply but am really over it right now... I pack spare clothes in DD's nappy bag incase SHE wets herself or chucks... not incase her cup leaks!!!!

Has anyone used the Tommy Tipee one? What do you think of those?

Advice would be great!

Thanks

MG