2001.07.20 15:50 "Re: LZW TIFFReadScanline woes", by Terry Wells
The optimizer in VC++ 5 had quite a few bugs in it. VC++ 6 seems much better.
Back to the original problem...
Sean: You said that you were subsampling the image by skipping scanlines when reading. Perhaps something to try would be to read all the scanlines into your buffer even though you ignore some of them. If the lzw decompressor had a bug where it failed to properly decode lines out of order, this would workaround it.