changing lofts and lies of drivers and fairway woods

is it legal during a round to change the settings(loft and lie) of the neww woods?

I've been told no.  My golf coach told me this, and when I was watching the Masters it came up.  Phil was preparing to hit his tee shot when he noticed the head of his adjustable driver was loose.  Before he tightened it, he had to check with rules to make sure that he wasn't breaking this rule.  Tightening, yes; adjusting, no.

I read somewhere (may have been Golf Digest under "Rules Guy") that you can't adjust a club during a round (vary the loft or lie angle). 

Hi guys,

Here is the ruling from the USGA on adjusting a club during the round...

 Adjustability 
(From http://www.usga.org/Rule-Books/Rules-on-Clubs-and-Balls/Clubs/#adjust)

Appendix II, 1b provides that:

All clubs may incorporate features for weight adjustment. Other forms of adjustability may also be permitted upon evaluation by the USGA. The following requirements apply to all permissible methods of adjustment:

(i) the adjustment cannot be readily made;

(ii) all adjustable parts are firmly fixed and there is no reasonable likelihood of them working loose during a round; and

(iii) all configurations of adjustment conform with the Rules.

During a stipulated round, the playing characteristics of a club must not be purposely changed by adjustment or by any other means (see Rule 4-2a).

Playing Characteristics Changed (Rule 4-2a)

Rule 4-2a provides that:

During a stipulated round, the playing characteristics of a club must not be purposely changed by adjustment or by any other means.

The purpose of this Rule is to prevent the player from purposely modifying his club during the round, such as modifying a club’s lie or loft, adjusting weight or changing the head and/or shaft, regardless of whether the club has been designed to be adjustable.