I hesitated for a long time to post about this glitch but I'd love to get back to another playthrough of NV but it's unusable without Darn, so here goes nothing: Been reinstalling many times, this example is straight off a fresh download through steam and even with the TTW version of Darn UI (TTW 3.0 / Alpha 9.7). I've had this issue with the last available version Darn himself published:

http://postimg.org/image/lhtpjtruj/

Whenever an ammo type has more than 2 effects, the transparent list becomes an ugly filled box. Digging through all the XMLs that Darn installs, I didn't find any obvious alpha changes that would allow this. Vanilla, of course, doesn't have any boxes for lists. During my last attempt a few months ago, I even tried every single iteration of the older Darn versions until the issue appeared; The old ones didn't modify enough of the UI to have it.

If someone could guide me into the right direction, it'd be immensely appreciated.

Edit: The last official DarnUI mentioned something called "expanded effects list" in the to-do that was never finished. Does anyone else even have this problem?

Are you using any other mods that might have made changes to the UI such as Project Nevada, quite a few of the mods made by Gopher. If so you might need to install a mod that allows more than one UI mod to play well with others. I forgot the name of it.

Thanks for your reply, Erzherzog Hans,

To pinpoint the glitch, this screenshot is from a clean install (Steam) with *only* DarnUI and AWOP installed.

(AWOP adds a shack in which a vendor happens to sell +P ammo with the 3 effects.)

No other HUD mod(s). The last time I installed about 90 additional mods afterwards, it didn't change the effect list, looked just the same.

Only once had I managed to broke the HUD as severe as to somehow remove the rectangle around the box but messing up positioning instead.

I have programming experience, so I might be able to fix it myself, if someone could tell me where to start.

Try with only DarnUI.

Maybe AWOP needs a compatibility patch to work with DarnUI.

I only used AWOP for a short time in NV since to me it does not fit in that well with the game like it did for FO3. I also do not use DarnUI since to me it is not finished.