For a solution, I was just surfing and came to pod2g's iOS blog which says that a fix is currently in the works and will be pushed to Cydia soon.
If you are a power-user, and want to fix the situation already, here is a script that forces a rebuild of com.apple.mobile.installation.plist :
chmod -x /usr/libexec/mobile_installation_proxy
killall -9 mobile_installation_proxy
rm /var/mobile/Library/Caches/com.apple.mobile.installation.plist /var/mobile/Library/Caches/com.apple.LaunchServices-045.csstore
launchctl stop com.apple.mobile.installd
launchctl start com.apple.mobile.installd
while [ ! -f /var/mobile/Library/Caches/com.apple.mobile.installation.plist ];
while [ ! -f /var/mobile/Library/Caches/com.apple.LaunchServices-045.csstore ];
chmod +x /usr/libexec/mobile_installation_proxy
Before trying it, make sure to do a backup. It has already been thoroughly tested, but it is safer.
You can get back to pod2g's iOS blog or Twitter for more clarification.