Yes, I have had that when I very first started running a forum, and it annoys me to no end. Members sometimes just don't get the fact that we admins do have lives outside our forums, that we can't be on 24/7 to fix a problem, and for those of us who are free hosts, like me, people don't realize that there is only so much to do on a free host. I don't know what to think anymore. In fact, just today I had a request for topic icons == we are on a free host people! I know you don't like that but I do. I could hunt around in the ACP for something like that, but otherwise, unless I make a request in the support forum, there's nothing I can do about it. Also, if you are able to do it, but you're still low on time, and you hear: "are you done yet, are you done yet?" It goes back to what I said earlier. We do have lives outside our forums. We can't be there 24/7 to go to the support forum with requests for mods, or to mess around in the ACP... It just drives me crazy to no end.
It happens that people do rush you at times, it can be a little annoying but the best policy is probably to simply explain that things take time and that you will get to them. It's usually new inexperienced members that don't understand how things work, that rush you in this way.
I'd say for me, its mainly me making myself feel rushed. If something on the forum is messed up, I feel obligated to fix it ASAP. Suppose the best member ever were to visit my site at that point in time (when the site is messed up)... I'd probably lose him! T_T