Tweek

Have you changed your mapvotecycle.cfg? It has to be changed to gametype 6 as well. I have  just six in my rotation but 32 can be voted on.  This is what mine looks like.
 
// silEnT mod - Sample MapVote cycle file

// Each map in this map order is executed whenever there are no votes for a map,
// otherwise, the map that gets the most votes for is played
set d1 "set g_gametype 6 ; map oasis_winter ; set nextmap vstr d2"
set d2 "set g_gametype 6 ; map battery_recharged ; set nextmap vstr d3"
set d3 "set g_gametype 6 ; map goldrush-ga ; set nextmap vstr d4"
set d4 "set g_gametype 6 ; map radar ; set nextmap vstr d5"
set d5 "set g_gametype 6 ; map railgun ; set nextmap vstr d6"
set d6 "set g_gametype 6 ; map fueldump_revenge ; set nextmap vstr d1"
vstr d1

When someone calls a vote that person is automatically defaulted to yes on vote. You can easily disable that voting option though by doing this.
Put this in your server config:
 
set vote_allow_putspec 0
 
Any vote can be disabled if abused. Check out all your voting server cvars here:
 
http://mygamingtalk.com/wiki/index.php/Silent_Mod_Server_Cvar#Voting
 
Also you can change the percent of people it takes to pass a vote as well. I suggest you read through all the voting cvars and customize to your liking so you wont have any problems in the future.