Fore Example, this one:

Function VEPT_Pre(Sigma, ProcessTime, MTTF, MTTR)
'Variance of effective Process Time page 262 Formula 8.6
'pre-emtive failures
VEPT_Pre = (Sigma / Availability(MTTF, MTTR)) ^ 2 + _
((2 * ProcessTime * MTTR * (1 - Availability(MTTF, MTTR))) /
Availability(MTTF, MTTR))

End Function

It is in a cell in the worksheet and was working fine in 2001, but now in
2007, changes to #NAME? if I cause it to rebuild, for example by clicking on
the cell so that it shows in the formula bar, then putting the cursor at the
end & hitting enter.

I tried adding "Public" but there was no effect. This and other function are
in "Module1" If I click on an empty cell and then click the Insert Function
fx spot, the name shows, but it is telling me that the function takes no
arguments. You can clearly see the arguments above.

One by one my precious formulas upon which my grade for my summer course
entirely depends, are being eaten by 2007, and summer is about over so all I
can say is: HELP!
Thank You,
-plh