I've used Acquisition for years under Mac OS 10.3.x. Always I would recommend it for P2P business. I recently upgraded to mac OS 10.4.8 and now Acquisition "loads core components" which apparently make it operate better...(over the network?, on my computer OS?). However, I can no longer download because of the "router ports need to be configured" issue in the Preferences...Network pane. I've follow all the advice for non Airport routers (mine's a Linksys router...worked just find pre-10.4.x use). The software changed it's operation under 10.4.x, it's now not operating as before (no downloading), and I've sent several emails to the feedback@acquisitionx.com address in the application...and...NO RESPONSE from the developer, David Watanabe. Wow, don't I feel appreciated as a paid customer. (Maybe, if I'm lucky, he's on vacation and I'll get a response tomorrow.)