It seems sqlite3 has a database corruption bug since 3.6.16, that was fixed in 3.7.2.
Please consider updating POCO 1.3.7/1.4.0 with sqlite 3.7.2.
More info at:
POCO looks like an amazing library. I'm looking forward to using POCO for the 1st time on my current project (specifically for ZIP, sqlite3, networking, and multithreading.) I've checked out POCO 1.3.7 and will probably start using it this week.