  Dijet production in deep inelastic ep scattering is investigated in the
region of low values of the Bjorken-variable x (10^-4 < x < 10^-2) and low
photon virtualities Q^2 (5 < Q^2 < 100 GeV^2). The measured dijet cross
sections are compared with perturbative QCD calculations in next-to-leading
order. For most dijet variables studied, these calculations can provide a
reasonable description of the data over the full phase space region covered,
including the region of very low x. However, large discrepancies are observed
for events with small separation in azimuth between the two highest transverse
momentum jets. This region of phase space is described better by predictions
based on the CCFM evolution equation, which incorporates k_t factorized
unintegrated parton distributions. A reasonable description is also obtained
using the Color Dipole Model or models incorporating virtual photon structure.
