Question: Error when using pdsolve

I'm trying to solve a 2nd order system of pde's with couplded BC but it gives me the following error

Error, (in pdsolve/numeric) initial/boundary conditions must be defined at one or two points for each independent variable

Here is the code

> T01 := 273; T02 := 26; L1 := .1; L2 := .2; h1 := 100; h2 := 200; k1 := 1; k2 := 2; rho1 := 1000; rho2 := 2000; c1 := 0.1e6; c2 := 0.2e6; alpha1 := 1; alpha2 := 2

> PDE := {diff(T1(x, t), t) = (diff(T1(x, t), x, x))/alpha1, diff(T2(x, t), t) = (diff(T2(x, t), x, x))/alpha2}

> IBC:={k1*(D[1](T1))(L1, t) = k2*(D[1](T2))(L1, t), T1(L1, t) = T2(L1, t), T1(x, 0) = T02, T2(x, 0) = T02, (D[1](T1))(0, t) = -h1*(T1(0, t)-T01)/k1, (D[1](T2))(L1+L2, t) = h2*(T2(L1+L2, t)-T02)/k2}

> pds := pdsolve(PDE, IBC, numeric)

Its basically a 1D heat equation in a 2 layers plate with conduction BC on both sides