UDM4 not working with prototype?

[inky]

Is there an incompatability problem when using UDM4 and the prototype framework?

Our site's been using UDM4 happily for a while now, but we are implementing the prototype javascript framework and have encountered problems. Specifically, if we load prototype.js then some of our html SELECTs start misbehaving, i.e. when the page loads the select appears correctly for a fraction of a second, then goes completely blank.

If we disable UDM4 on the page, everything works fine.

This only occurs with IE (version 7 tested), FF 3.03 does not exhibit the problem. No javascript errors reported by IE and no errors or warnings from firebug.

Any advice appreciated!!