  We measured the angular dependence of the c-axis magnetoresistance rho_c(B)
of Bi-2212 irradiated with heavy ions. At temperatures near 68 K the scaling of
rho_c(B) with the c-axis magnetic field component B_perp is broken and the
in-plane field, B_parallel, affects rho_c. At this temperature, at a specific
field B_cr \approx B_Phi/2, magnetoresistance becomes independent of field
orientation. This crossing point allows us to estimate the correlation length L
of pancake positions along the c axis. We find L/s is about 100 at B=B_cr,
where s is the interlayer spacing. This provides evidence of strong enhancement
of pancake alignment in the vortex liquid in crystals with columnar defects.
