plot.background only shows 3 out of 4 lines - r

Question

I'm experiencing a problem when using ggplot. my code shoud afaik give me a frame around the whole plot using (plot.background = element_rect(color="black"). However I only get 3 out of four lines. Any ideas on how to get 4 out of 4?
I have this theme:
theme.plot.bar <- function(){
theme(
text = element_text(family = "sans", face = "plain", colour = "black", size = 12, hjust = 0.5, vjust = 0.5, angle = 0, lineheight = 0.9),
axis.text.x = element_text(size = 13, colour = "black"),
axis.text.y = element_text(size = 11, colour = "black"),
strip.text = element_text(size = rel(0.8)),
axis.text.x = element_text(vjust = 1),
axis.text.y = element_text(hjust = 1),
axis.ticks = element_blank(),
axis.title.x = element_text(),
axis.title.y = element_text(angle = 90),
panel.background = element_rect(fill = NA ,colour = NA),
panel.grid.major.x = element_blank(),
panel.grid.minor = element_blank(),
panel.grid.major.y = element_line(colour = "black", linetype= "dotted", size =0.6),
strip.text.x = element_text(),
strip.text.y = element_text(angle = -90),
plot.background = element_rect(colour = "black", size = 0.5, linetype= 1, fill="white"), # Kant i højre side kommer ikke med hvis den sættes?
plot.margin = unit(c(0, 1, 0, 0), "cm"),
complete = FALSE)
}
Which gives me this output with ggplot:
EDIT: with plot.margin changed to 3 cm:
EDIT 2: with session info and ggplot-code as requested
NB: It still dont work when setting all plot margings as 2 inhes. I use png
sessionInfo()
R version 2.15.3 (2013-03-01)
Platform: x86_64-w64-mingw32/x64 (64-bit)
x <- factor(pol$job_komp_v2)
df <- as.data.frame(na.omit(x))
names(df) <- "v1"
farve <- rgb(144,26,30, maxColorValue =255)
r <- ggplot(df,aes(x=v1)) +
geom_bar(aes(y = (..count..)/sum(..count..)),
fill=farve, width=0.35) +
scale_y_continuous(labels = percent, "", limits=c(0,1), breaks= c(0,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1)) +
scale_x_discrete(name= "") +
theme.plot.bar()
r