Few weeks ago, first Foursquare application and then my favorite RunKeeper app started to fail. The symptoms were simple:

1) attempt to start

2) wait for for 2-10 seconds

3) exit

Analysis of the crash logs did not reveal anything obvious (see ~/Library/Logs/CrashReporter/MobileDevice/NAME:

[code language="xml"]

Process:         foursquare [374]
Path:            /var/mobile/Applications/7F37347B-......1663AA5/foursquare.app/foursquare
Identifier:      foursquare
Version:         ??? (???)
Code Type:       ARM (Native)
Parent Process:  launchd [1]

Date/Time:       2009-12-22 12:39:11.260 -0500
OS Version:      iPhone OS 3.1.2 (7D11)
Report Version:  104

Exception Type:  EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x20294628
Crashed Thread:  0

Thread 0 Crashed:
0   libobjc.A.dylib                   0x32668ecc 0x32665000 + 16076
1   CoreFoundation                    0x32d83d6a 0x32d4d000 + 224618
2   CoreFoundation                    0x32d4fc28 0x32d4d000 + 11304

[/code]

What helped was to delete both applications from the phone, including data and let the iTunes install it back. No data is lost, because both services are cloud based - only minor inconvenience was to re-enter login information.

So, Nael - I am back in the game and cannot wait to claim back mayorships for all places I have been ousted :-)