also check your arc.ini
Code:
[External compressor:pzlib]
header = 0
unpackcmd = pzlib d -t8 - -o - <stdin> <stdout>
post#71 has the following & used x86 version NOT x64 versions.
Code:
packcmd = pZLib e -m2 -st50p -ct8 -b1024k - -o - <stdin> <stdout>
simple copy / paste into your arc.ini to see if it helps any, try using pZLib instead of pzlib
don't think it matters any but try as suggested.