libraries in .First

Dear all,

    I have a question regarding the .First function. I have included 
help.start() and several libraries in my .First as:

.First <- function() {
help.start(browser = "netscape7")
library(lattice)
library(modreg)
library(splines)
library(MASS)
library(maps)}

The libraries maps and splines do not seem to be available when I start 
R, but I have found if I change the order of the libraries in .First, 
these libraries may be available and others may not. Has anyone had a 
similar problem, or could anyone offer some suggestions? Thank you!

Laurie Sindlinger