fminbnd error while solving the neoclassical growth model

I am using fminbnd to solve the neoclassical growth model and I have the following code for main.m

clear all;
close all;
tic
global v0 beta delta alpha kmat k0 s

%set up the fixed paramters
alpha = 0.33; %capital share
beta = 0.95;%discount rate
delta = 0.1; %rate of depreciation of capital
s = 2;


tol = 0.01;%tolerance
maxits = 1000;%maximum iteration
dif = tol + 100;
its = 0;

kstar = (alpha/(1/beta-(1-delta)))^(1/(1-alpha));
cstar = kstar^(alpha)-delta*kstar;
istar = delta * kstar;
ystar = kstar ^ alpha;

kmin = 0.25*kstar;
kmax = 1.75*kstar;
kgrid = 99;
grid = (kmax - kmin)/kgrid;
kmat = kmin:grid:kmax;
kmat = kmat';
[N,n] = size(kmat);

polfun = zeros(kgrid+1,3);

while dif>tol && its < maxits
    for i = 1:N
        k0 = kmat(i,1);
        k1 = fminbnd(@valfun,kmin,kmax);%continuous choice set, so it will search over all values 
        %of k1 between kmin and kmax. For this reason, we need to
        %interpolate values of the value function off of the grid
        v1(i,1) = -valfun(k1);
        k11(i,1) = k1;
    end
    dif = norm(v1-v0);
    v0=v1;
    its = its + 1;
end
for i = 1:N
    con(i,1) = kmat(i,1)^alpha - k11(i,1) + (1-delta)*kmat(i,1);
    polfun(i,1) = kmat(i,1)^(alpha) - k11(i,1) + (1-delta)*kmat(i,1);
end
toc

The value function valfun.m is as follows:

function val=valfun(k)

% This program gets the value function for a neoclassical growth model with
% no uncertainty and CRRA utility

global v0 beta delta alpha kmat k0 s

g = interp1(kmat,v0,k,'linear'); % smooths out previous value function

c = k0^alpha - k + (1 - delta)*k0; % consumption
if c<=0
    val = - 888888888888888888 - 800*abs(c); % keeps it from going negative
else
    val=(1/(1 - s))*(c^(1-s)-1) + beta*g;
end
val = -val; 

When I run, I keep getting the following error:

Error using interp1>reshapeAndSortXandV (line 447)
LENGTH(X) and SIZE(V,1) must be the same.

Error in interp1 (line 128)
[X,V,orig_size_v] = reshapeAndSortXandV(X,V);

Error in valfun (line 8)
g = interp1(kmat,v0,k,'linear'); % smooths out previous value function

Error in fminbnd (line 232)
x= xf; fx = funfcn(x,varargin{:});

Error in main (line 38)
k1 = fminbnd(@valfun,kmin,kmax);%continuous choice set, so it will search over all values

I am not sure what I am doing wrong. I think I followed all the steps to set up fminbnd as in the online help.

Thanks

[Torsten]

kmat and v0 must be of the same size in order to use interp1.