There have been some issues with the AppWorld services lately...most are reported to be cleared up. Please try again. Also, please try removing and re-installing AppWorld...some have reported that to be helpful. In addition...RIM has released AppWorld version 188.8.131.52...it is highly recommended to be on that version.
Also please try a hard reset: With power ON, remove the back cover and pull out the battery. Wait about a minute then replace the battery and cover. Power up and wait patiently through the long reboot -- ~5 minutes. See if things have returned to good operation. Like all computing devices, BB's suffer from memory leaks and such...with a hard reboot being the best cure.
In addition, you can try this sequence:
1) Remove AppWorld from your BB (Homescreen > Options > Advanced Options > Applications) -- if it requests that you reboot the BB, do so.
2) Do a Batt-Pull reboot as described above.
3) Get a new link and install a fresh copy of AppWorld
Occam's Razor nearly always applies when troubleshooting technology issues!
If anyone has been helpful to you, please show your appreciation by clicking the button inside of their post. Please click here and read, along with the threads to which it links, for helpful information to guide you as you proceed. I always recommend that you treat your BlackBerry like any other computing device, including using a regular backup schedule...click here for an article with instructions.