I knew I was forgetting something... I also knew it was something to do with the vid drivers used, and in this case, the dds compression tool used.
Ahhh well, glad you have it working now. Most of this stuff, well, I use the same routines for everything, so I sometimes forget to tell folks what I have had to do.
1) Create/modify whatever original TGA
2) Flatten all layers.
3) convert to dds, and yes, I always used the dds tool that OMB linked with.
Going other way, from DDS to TGA
1) Export dds, typically using nwnexplorer, but sometimes just copying that file out of a hak etc.
2) convert to tga with following steps
..a) copy and original .dds files to a sub folder called ..\\in
..
run the dds2tga.bat file
cd in
REM First we rename all *.DDS to *. so we can remove the .DDS extension
REM For the mipmap processing
ren *.dds *.
REM Cycle every *. in the /in/ directory
FOR %%i in (*.) DO (
ECHO Processing %%i.dds
REM Rename it back to a .DDS
ren %%i %%i.dds
REM Convert it from DDS to TGA
..\\DDSTools.exe -d %%i.dds
REM delete the mipmaps
IF EXIST %%i1.tga DEL %%i1.tga
IF EXIST %%i2.tga DEL %%i2.tga
IF EXIST %%i3.tga DEL %%i3.tga
IF EXIST %%i4.tga DEL %%i4.tga
IF EXIST %%i5.tga DEL %%i5.tga
IF EXIST %%i6.tga DEL %%i6.tga
IF EXIST %%i7.tga DEL %%i7.tga
IF EXIST %%i8.tga DEL %%i8.tga
IF EXIST %%i9.tga DEL %%i9.tga
IF EXIST %%i10.tga DEL %%i10.tga
REM Rename the 0 to remove the 0 index
IF EXIST %%i0.tga ren %%i0.tga %%i.tga
REM And move it to the /out/ folder
IF EXIST %%i.tga move %%i.tga ..\\out\\
)
pause
..c) run tga_flipper.exe twice on the files. Taking ..\\out as input first time, and exporting to ..\\in then doing the tga_flipper.exe again using ..\\in and placing output into ..\\out.
Anyway, that seems to solve 99.9% of any issues I have with DDS-TGA conversions.
Note that I have not had an ATI card, since, well, long, long time. I used to swear by ATI, but when I first purchased NWN, I had considerable difficulty with the card I had, and switched to NVidia... problems were vastly reduced by going that route.
I don't bother updating vid cards, unless I am also upgrading main cpu as well, and as such, have not upgraded in a few years, but so far, have not seen a reason to go purchase the latest/greatest/most expensive vid cards, since they truly don't offer that much more with the cpu setup I have.
Next pc will have all the greatest crap available, and then must last me at least 5 years, which my current pc has done other than 2 failed vid cards. It is pushing the envelope now though, on just how much more use I can get out of it. Fine for NWN, and even some of the latest games, but is locked down with XP and directx9c, and not worth upgrading to Win 7 as I would have to purchase ram and this motherboard only takes a max of 8 gig regardless of OS.
Anyway, good to hear you have things working now.