I narrowed down the issue to 1Password items in the list... it seems I am able to set priority on other items. I have posted an issue here https://github.com/quicksilver/Quicksilver/issues/364. Thank you -
- [QSb60] can't re-prioritize list item Steve
- Re: [QSb60] can't re-prioritize list item Rob McBroom
- Re: [QSb60] can't re-prioritize list item Steve
