Can't increase uGridsToLoad above 5 in INI

From this page: http://www.tweakguides.com/Oblivion_9.html

uGridsToLoad=5 - Increasing the uGridsToLoad value (always in odd steps of 5,7,9,11 etc.) will increase the number of grids around the character in which full texture data will be loaded up and visible as he/she wanders around. This clearly improves visual quality - removing blurry distant LOD textures for example when set to 11 or above - however it also noticeably increases loading times and loading pauses, introduces visual anomalies (particularly around water areas) and reduces performance significantly. Interestingly, as uGridsToLoad increases, the system automatically increases the uExterior Cell Buffer value to accommodate the greater cell data. Furthermore, if you use an even value, the engine will automatically raise it to the nearest odd value (e.g. entering 10 means the engine will set it to 11). On balance the default value of 5 is a good compromise between performance and loading pauses.

Importantly: Instead of using the above variable to improve distant textures, particularly the blurry land textures, it is strongly recommended that you instead use the Landscape LOD Replacement Mods as detailed in the Patches & Mods section of this guide on Page 4. These mods provide far less of a performance decrease for a similar effect, and don't result in the types of glitches which altering the uGridsToLoad variable can bring with it.

So, maybe you should not be using this variable anyway.