This thread gives the settings to use for both Max and ZBrush when importing and exporting models using these plugins.
IF YOUR MODEL IS IMPORTING INTO ZBRUSH WITH THE UV’S TRIANGULATED, FIRST CHECK TO MAKE SURE THAT “# OF DIGITS” IS SET TO 6 IN THE MAX EXPORT DIALOGUE. IF THAT DOESN’T RESOLVE THE PROBLEM, RESET THE xFORM FOR THE MESH.
ZBrush 3 Threads
Preferences>Importexport settings to use.
Helpful info for Max 2008 users
Helpful info for Max 2009 users
Supplemental Threads
A very helpful troubleshooting thread
Animation test with detailed settings
Preventing point reorder when exporting from Max
More info about displacements in Max
Max 8 Tangent Settings for ZMapper (See first post)