What you can do to make that work is get rid of the d3d8.dll that came with widescreen fix and instead use ultimate asi loader. Rename h3w.dll to h3w.asi. And if you want, you can use d3d8to9 that comes with ultimate asi loader. Create a global.ini in a folder called scripts and put the following in it:
[GlobalSets]
LoadPlugins=1
LoadFromScriptsOnly=1
DontLoadFromDllMain=1
FindModule=0
UseD3D8to9=1
DisableCrashDumps=0
Direct3D8DisableMaximizedWindowedModeShim=0