Why some of my motorola droid apps are not working?

I personally don't recommend factory mode myself; it is used in dire cases, and this doesn't seem like one that requires resetting. The problem may have occurred because of many reasons, all of which I am listing below:1. Your cellphone has lower internal memory available than the memory required by the application to run. You should remember that nearly all the android applications run on internal memory. So, if that is the case, clear some files from the internal memory before trying to install your application.2. Your mobile does not meet the graphic specifications needed by the application. Most of the android applications need good graphics, and, as far as I know, Motorola graphic-card is not that great. Also, there's a separate graphic card memory in the mobile that the applications use, apart from internal memory. If it's the former case, you have no choice but not to use the application. If latter's the case, remove some of the applications before installing yours.3. Scan your mobile for viruses. That may be the reason for hanging of these applications.4. Check out your network services. These applications rely heavily on the network, and any discrepancy in the service can lead to their non-functional state. Try to use your network service on someone else's phone and see whether the problem occurs there as well. If yes, talk to the network operator. If no, there is some problem in the mobile-hardware itself. In that case, check out the service center of your cellphone.I hope the above suggestions may work for you.