[Steve in Pudsey]

Quite a fair bit of US preschool stuff gets redubbed with British voices, though it seems to be inconsistent which shows get redubbed and which don't. And the UK dubs are often quite poor as well. Never entirely seen the point in why they do it, especially when I don't think it's ever been done for cartoons aimed at older viewers (I guess a slight exception was when Hanna Barbera made a series of Superted, and they got Derek Griffiths and Jon Pertwee back for the UK rather than keep the replacement US voices, which you can understand). I can only imagine they don't want really young kids picking up US accents and words while they're developing language skills... though the fact plenty of preschool shows go undubbed negates that.

Thinking back, there was quite a controversy about introducing Sesame Street in the UK back in the day with the IBA getting involved.

I only discovered today that Bob the Builder got dubbed in the US, with Greg Proops (of Whose Line etc) as the lead character for some seasons.