If there are no bans in that list, then the channel, technically, has no bans.
However, if there is a bot, or a script that tracks bans that are placed, they may re-issue a ban if someone that matches a previously issued ban joins the channel.
There is no way for any of us to know if the situation I just mentioned exists, or for us to tell you how you can get around it.
You can try typing the following in the channel window. Make sure you have ops in the channel before you use this.
//mode $chan -b *!*@WRNET-B5EFB4D5.mibbit.com
make sure you type that EXACTLY