I was having trouble with several (around 8) applications failing to update on the market so I just decided to wipe the data/cache, installed a new rom/kernel applied the market fix and reinstalled all of my apps. It went as expected except that a couple of the apps that I had installed on the sd card refuse to install with an "installation error" "unknown reason -18" in the market. I'm not sure how to debug this problem but I've looked through the phone and don't see any references to any stale files after wiping the data twice and reinstalling... Anyone have any ideas what to do? I should point out that even my titanium backups fail to install anymore. I have had no trouble recovering other programs and settings from the backups. The current apps in question are Google Sky Maps and Network Discovery.