United States v. Jackson, __ F.3d __ (5th Cir. Jun. 20, 2006) (sentence for possession of a firearm affirmed over a claim that district court violated constitutional rights by "threatening" defendants girlfriend with criminal prosecution if she took the stand during sentencing).
http://caselaw.lp.findlaw.com/data2/circs/5th/0511094cr0p.pdf