<p>What compatibility issues have you found when developing with Visual FoxPro 9 on Windows Vista?</p>

My company has no current plans to move to vista, so we haven't tested compatability issues yet.   Doug Hennig has an excellent article on the subject however:
http://my.advisor.com/articles.nsf/aid/18897
These links describe some issues as well:
http://fox.wikis.com/wc.dll?Wiki~VistaAeroIssues~VFP
http://fox.wikis.com/wc.dll?Wiki~SP2problemwithVistaandBorderstyle~VFP