Some time ago i posted this on delphigamedev so perhaps i'll link it here:
http://www.delphigamedev.com/forums/viewtopic.php?t=292

The thing was about fixing some of the known DelphiX bugs and adding there something new. Still the problem with textures is unsolved, however access violation is gone forever. It occures when DXDraw is resized or Ctrl+Alt+Del is pressed (so you can't escape it with anything else than fixing the core).

And forgot to mention, 1024x256 textures don't work, but 512x512 do, when patternsize is 256x256 on both cases I don't know why but to me it looks like delphix loads that 1024x256 and stretches it to power of 2 -> 1024x1024 and then use same texture for all patterns just with different texture coordinates. I'd find it wiser to make own texture for each pattern...