The standard Lutron dimmable switch will not work well with
fluorescents. Lutron makes a special switch (model number DVFTU-5A3P)
that works with dimmable fluorescents.
I went through a month or so of issues with the dimmable fluorescents
before I got this to work correctly.
In addition, no bulb was worth its salt except for the Philips
Marathon Classic 65. And even then, mounting them in cans that fit
them perfectly creates more heat than they probably should have.
Philips refunded me for six bulbs that I purchased through
www.environmentallights.com. (this is a great company, by the way...a
very knowledgeable staff!.