From John Sylvester:

The help phone number for students and instructors  is 800-955-8275
At least for instructors, they answer pretty quickly

Some problems with fonts (i.e wrong characters appear when user types)
are caused by anti-keylogging software distributed by comcast.
The guys at the help number know what to do.

In some problems that require two numbers as answers (e.g. the x and y
coordinates of a point in a circle), webassign will report that the x
coordinate is correct if it is in within 2 percent of the correct
value. If the y-coordinate is much smaller than the x-coordinate, this
2 percent error in the x-coordinate will be amplified so that it is
now impossible to get the y-coordinate correct.

Advice to avoid these problems

	       Enter exact answers
	       (pi, not 3.1415926535897984626....) or
	       exact fractions whenever you can.
	       On questions requiring a calculator,
	       keep all the decimal digits in intermediate
	       calculations, and only round at the end.

	       What webassign counts as correct:

	       For numeric answers (no calcPad pops up), the
	       default tolerance is 2%.

	       For symbolic answers (calcPad pops up), the
	       default tolerance is 0.001.

	       However, on some problems, a FRACTION mode
	       is invoked, with 0 tolerance, e.g.
	       1/3 is correct, but 0.333333333333333 is not.
	       (At this point, I don't know how to tell if you're in
	       fraction mode)
Function notation:
  Include parentheses with trig functions and exponential notation: 
  use sin(3x) e^(3x) ln(3x) not sin 3x, e^3x, nor ln 3x
  sin 3x may be interpreted as (sin 3)x by Web assign similarly e^3x
   is interpreted as (e^3)times x.
  It may also help to avoid extraneous spaces: use sin(3x) not sin (3x)