axes start at end of plot

Hello all, I used the following script to generate a plot, but when I 
try to place axes, the axes start at the end of my plot and continue off 
the plot; the attached image shows what happens when I try to generate 
axes.

library(fields)
as.matrix(read.table("Matrix.txt", sep="\t"))->x

#the matrix is a square matrix measuring 104x104; it was too large to attach

#on left: labels are:
Side<-as.character(x[1,2:ncol(x)])
length(Side)->nS

#on bottom, labels are:
Bot<-as.character(x[2:nrow(x),1])
x[-1,-1]->x
25->x[x>=25]
HeatBrk<-seq(5,25,4)
MyCol= gray((4:0)/4)
image.plot(x, col=MyCol, breaks=HeatBrk, legend.shrink=0.3, axes = FALSE)

axis(2,las=2, at = 1:nS, label = Side, tick = TRUE)
axis(1,las=2, at = 1:nS, label = Bot, tick = TRUE)

Any help would be much appreciated.

Thanks,
Sumukh