Just look at the imaging and printing business, HP's top-performing unit and analysts' favorite candidate for a spinoff. Cracks are starting to show as it comes under cutthroat pricing pressure from Lexmark (NYSE:LXK), Canon (NYSE:CAJ), and now Dell (NYSE:DELL). Sales are up by 3% from last year, but profits are down by 3.6%. Operating margins for the unit shrunk to 15.4% this quarter from 16.6% in Q4.