When I last tried running iSiloX on both OS X and Windows I noticed some differences in the files created. I previously posted on this issue early in 2005.
Out of interest I tried building the same document on both platforms again to see iff this issue was still present. Again I found that the Mac file was around 25% larger (8.5M vs. 6.7M) and additional material had been pulled in at the back end of the document (139 chapters vs. 72 chapters).
Interestingly the problem only occurs on more complex documents. The document in question is a complete Sherlock Holmes and the IXL file builds the individual books plus a single complete version. This latter version is more complex in structure.
As before the IXL files are from a common source with paths etc editied to match the platform requirements. Both are build as UTF-8 but have also been built as Windows-1252.