why do this one person disappear from my custom setting on facebook?

[telikahoward]

I use the custom setting to keep certain people from seeing certain statuses via facebook. well this one person who i want to stay on the custom setting always pops off the custom setting especially after i post via my cellphone. i thought it might be my phone thats causing it but the other person thats always on my custom setting never disappear. and its odd because right after that person can see my statuses again they immediately let me know by making an odd comment via inbox about the status. so now im thinking that maybe they know how to hack me or hack themselves off of custom? but my password is very hard so i dont know how they could do it. has anyone else experienced this? i cant delete or block this person because they are family and i know that this person will confront me about it (even tho im getting very tempted)

[Daniel]

Either your Account is Being Hacked and Somebody is Changing your Settings Around or it Could be a Error With Facebook