I Can Has Cheezburger 1.5.3 crashes immediately at startup because the feed it uses is broken. You don’t have to email me to let me know – I get about 10 reports a day.
Apple still hasn’t approved version 1.5.4 free although they approved 1.5.4 Pro in 24 hours. The updated version uses a different feed which I’m hosting myself. See this post from Dec. 24 which gives the gory details about why 1.5.3 crashes.