Siri won't open Pandora on my iPhone 4S

Just began having same Siri problem - the day after a successful demo of many Siri capabilities. I wish to try your proposed solution - using an iMac OS10.8.4 - have Ecamm' PhoneView but can't locate the files in question - please confirm they are iPad (iOS 6.1.3) files - and if necessary, what other Mac app I can use to follow your advice. Cheers.

I had this problem too with the iPhone 5s after evasion. The file

/var/mobile/Library/Caches/com.apple.LaunchServices-045.csstore

is now

/var/mobile/Library/Caches/com.apple.LaunchServices-054.csstore

The other file name is the same.

Nonetheless, deleting these two files did it.

Of note: All my apps seemed present when I rebooted the iPhone, and Siri didn't seem to open anything. However, I realized it would open one app but not another. After trying again with some apps it didn't recognize, I realized it suddenly found them. Thus, give it a few minutes to rebuild the index even if it looks like all your apps are there.