QUALM

We have had qualms about collaborating with others in sponsoring events; it always seems to be a more vexing exercise than a productive one.

DEF:

1. A sudden feeling of sickness, faintness, or nausea.
2. A sudden disturbing feeling: qualms of homesickness.
3. An uneasy feeling about the propriety or rightness of a course of action.

(American Heritage)