The situation is that I have my software located on a popular scripts site. I noticed I had got a bad review at a time when my webserver was having problems. I have since moved to a new host and things are fine. I feel as though the rating likely came from something out of my control. Do you think it is unethical if I encourage people to give ratings on this site? I think it would unethical to encourage them to give a positive rating, but just to go and review the script on our demo page and the give it a rating/review?
You could contact the popular scripts site and inform them of the reason you believe you had a bad review and ask that it be removed.
For it to be truthful, I think you need to keep all reviews, including the negative ones. As for asking users or encouraging them to leave a good review.. I would believe it would best to present the question neutrally.
I see no problems in asking for reviews as long as you do not say positive reviews. As far as the bad review, best not to remove it but maybe you would be able to leave a review stating that you had server problems and everything is ok now and that you apologize for the inconvenience it caused anyone. Whatever you do, don't claim no fault, it tends to look like you are not willing to accept responsibility. In situation like this, defending yourself too much often leads to you looking worse. Good luck and one bad rating normally won't hurt you much.
yes, You can send you feedback to popular scripts site and inform them of the reason you believe you had a bad review and ask that it be removed.
You could even host those reviews by yourself: announce that you have "faster host now" and expecting comments (good or bad) from any of your clients. Make sure to show these reviews in public (like a forum or something).