Hey there - was it you who posted a 1 star review for UDisc? The issue you're experiencing is due to 1 of 2 things. Either you don't have the latest version of UDisc (please check for updates in the app store), or your phone needs to be rebooted.
On iPhone 4/4s, when the phone hasn't been rebooted for long periods of time, it slows down and is low on memory. If you reboot the device and then open UDisc -> Find Course, it will work fine. I'd appreciate if you would try that and update your review accordingly.
Thanks and please contact me by email if you have questions (firstname.lastname@example.org)