Spurious predictive text in webview forms

According to http://qt.gitorious.org/qt/x11-maemo/commit/b8102ec6d2f01a0aedf2ecd5bbf16d3a5f6c296e, predictive text and auto-uppercase should be disabled in input fields in QWebViews. However, in practice, predictive text seems to be enabled, spuriously, for some fields.

The attached minimal example project shows this issue - it simply displays a webview with three input fields.

Press the first field, and press one key on the keyboard - predictive text is added following the letter pressed.
Press the second field, and press the same key on the keyboard - only the character pressed is input, but in uppercase.
Press the third field, and press the same key on the keyboard - the right character is input, in lowercase, as expected.

The outcome of this is displayed in the attached screenshot.

The behaviour doesn't seem to be consistent, and as far as I can understand the commit above, all of this should be disabled. If that isn't the case, a way of disabling the predictive input and auto-uppercase is needed.