Hi there.
I'm using 1.61 and I've found two ways to work around this (for this you must have the latest catver.ini: catver_ini_file d:\mame\catver.ini).
1. Make several emulator.ini. Then generate the all-games list; and finally generate the Filtered game list with the category you want. With this method you swith from platform to platform (fighter to maze to shooters, etc).
2. Make several game lists ini: mame.ini, mame-1.ini, mame-2.ini, mame- 3.ini, mame-4.ini, etc. Once you generate the main list (all-games) you just start generating each game list with the category you want. This way you switch from game list to game list.
I personally like the first option cause I can have a differente layout for each mame category. For example, I made a fighter's layout for my fighting games, a stock racing layout for my driving games, a shooting gallery layout for the shooting games, etc. All you need is time.
Hope this helps.
Cheers,

Congui