Mouse and USB during games

It's not the mouse or the mouse software because i've had this issue for years thru several mice and all different software. Right now i have a roccat gaming mouse and the driver is the latest as is the desktop's USB driver. So i assume there is some sort of optimization that needs to be done.

Anyways, heres the issue... the 2 mouse buttons i have the most issue with are the 2 small buttons on either side of the scroll wheel. They get assigned to a keystroke, which i think is where the issue lies and hopefully there is a way to optomize it. When i hit the buttons they often do nothing till i have hit them several times. then at other times they will respond better. Likely due to how intensive the game is at a given point. It's not the buttons gone bad. I can take a text file and hit them 100 times in a row and it won't miss a beat. I also cannot use the button's default function in most games, as they wont bind or will change the mouse speed on some of them if thats what the function is. So i MUST be able to bind them to a key. Of course i don' know for sure that it's the fact they are bound to keystrokes that is causing this. So can anyone think of an optimization or something that might stop this issue from happening in games?

The model is a "Kone (+)" but i doubt that matters since all roccats probably use the same software. But it's not the software or the mouse. As i have said, this has been an issue since i started gaming many years ago thru several mice and software and many games. It just varies depending on the game and who knows what other variables. I'm just looking for system tweaks. Like the windows mouse settings have a setting for typing delay when you hold a key down, how long does it take before the key starts repeating the character. I set that as fast as it goes but no joy. But thats the kind of thing i'm talking about. I'm asking if anyone knows of any system tweaks like reg entries that might eliminate things like that repeat delay i mentioned. In fact, thats still suspect because you can only shorten the delay, not eliminate it. But in any case thats what i'm looking for.....system tweaks that are known to counter this common issue, and i say common because i did a google search and it is. Maybe a USB thing....USB is known to be slow and buggy. And yes, i tried a PS2 adapter but this mouse won't work in PS2. If it were the mouse software or the mouse i would think that thru many brands of mice and their software one would have worked by now. ALL of them still allowed this issue so it's not that.

Oh, and it;s not a issue of the mouse's special functions not being supported because the button thats causing the majority of my problems is bound to the "i" key, and I get the same issue if i press the i key on the keyboard.