I've seen that there is a lot of people wanting to modify their Windows Mobile 6 ROM in order to optimize the performance of this wonderful device. Alright, here is a how-to that I hope you find useful. Here they are steps you have to follow:

1. Get an editor that could modify files in hexadecimal mode, for instance UltraEdit (its demo version can save files)
2. Open your WM6 ROM (I think that it's also applicable to WM5, but I'm not sure)
3. With the editor we chose, we have to search this hexadecimal string:
   • String to search: 64 B0 00 00 64 00 00 00 74 9A 1F 80 00 00 48 00
   • Note: The number that determines the size of the paging pool is formed from the last two numbers "48 00", that is the equivalent in hexadecimal to 8 MB
   • It would be possible that your default value is different to "48 00". In that case, you might not find the string above. Then you should look for the string without the last part "48 00", that is 64 B0 00 00 64 00 00 00 74 9A 1F 80 00 00. The value to be modifed is the two pairs of numbers that come next to the searched string
4. To set the value to 0 you only have to change "48 00" by "00 00"
5. Save the file
6. Flash the device with the modified ROM

With this instructions it's all done. If you manage to get if flashed and working you can share your experiences via comments.

Good luck and thanks