Cydia Running Very Slow on iPhone 3GS After Greenpois0n Jailbreak

Hello Jimmer, have you tried to reset your phone’s network setting? To do that, just go to Settings -> General -> Reset -> Reset Network Settings. Also, have you added a new Cydia repo prior this error? If yes, then try to remove it and reboot your iOS device. You can follow this tutorial on how to uninstall broken Cydia repo / source from Cydia app.

Lastly, make sure you have the latest version of Cydia (version 1.1.1) installed on your jailbroken iPhone. If you have the old version, then I would recommend you to update your Cydia by following the tutorial posted below:

Step 1: Launch Cydia and go to Changes. Then under Changes tab,tap the Refresh button in the top left corner to start downloading the new Cydia 1.1.1.

Step 2: Once Cydia download is complete and all packages have been updated, the app will prompt you with the option to complete an Essential Upgrade in order to successfully install the new Cydia. This process will take few minutes as it also updates other repos, apps, and tweaks that you installed on your device.

Step 3: The app will prompt you to confirm the update. Just simply confirm it and wait for Cydia to complete all the necessary changes. Once done, just simply close Cydia app and you are good to go.