Hey Paul.....Ignore these nabobs. If you like your Ovation, you're in pretty good company with some other players so play what you like.

The dtring gauge difference will probably correct your problem but also have a very close look at where the e-string is placed. On some guitars the saddle may be a bit notched after the years, especially if it's plastic (replace that) and the string might be lying to close to the edge of the fretboard, especially farther up the neck. This would be very noticeable with a capo. Check too, as others have mentioned, for fret buzz.

We tend to forget how much effect on sound that a fretboard has, but it's a factor.

Spaw