Rafael and/or Jeff, The Win32 version of the affy devel package (1.3.4) only contains the doc subdirectory and the description file. I tried compiling from source, but I get lots of parse errors and 'declared function' errors. I can compile other packages (e.g., I can compile affycomp no problem), so I don't think this is a problem with Rtools or mingw. However, this does appear to be a Windows-specific problem because I *can* get affy 1.3.4 to compile on my Linux box (maybe a question for r-help?). Anyway, when you get a chance will you replace the win32 zip file? TIA Jim James W. MacDonald UMCCC Microarray Core Facility 1500 E. Medical Center Drive 7410 CCGC Ann Arbor MI 48109 734-647-5623