conceal carry at church fundraiser?

[Solaris]

But also, I would think you just received effective notice from the organizer

I do not think he did at all. Based on what OP wrote,

"This year, in addition to chicken wings, pizza, and soft drinks, we are also going to be selling beer. He mentioned that because of this, I can't conceal carry at the event."

The organizer was just relaying to him it would be a 51% location this year, that is not the same as giving 06/07 notice.

[srothstein]

Fortunately, the problem was cleared up by Dru, so this is kind of moot for this case, but it may be important to another case.

Unfortunately, for oral notification, the law does not provide any specific wording. You might be right, but I would be very cautious about carrying anywhere after any type of notice from someone who might be in charge, even if it was based on a mistaken belief that they would be 51%. I do not know what the courts would accept as effective notice. If someone doesn't say you cannot but says something like "Oh, we don't allow guns in here" is that good enough? Or does it have to be personalized to the effect of "You cannot carry a gun in here"?

If someone tells me I cannot carry because they are a 51% location, and I look on the TABC website and it is not a 51% license, have I received notice or not? I really do not know what a court would say about this, so I would probably not carry after any kind of notice like that.

I would also not be one to question who has apparent authority,a s a general rule. The exception to this is the one Dru used, accurate knowledge of the location and its employees. But at a strange location, I would accept it from almost any employee. Even ones who I think are clearly wrong, like the recent Whataburger employees who told the off-duty police officers to leave because they were carrying. It isn't worth the risk to me.

Obviously, these are the guidelines I use and recommend but you are free to, and encouraged to, make your own decisions on this. I just hope we have all thought about this type of vague notice in advance so we know how to react.

[ScottDLS]

Fortunately, the problem was cleared up by Dru, so this is kind of moot for this case, but it may be important to another case.

...
I would also not be one to question who has apparent authority,a s a general rule. The exception to this is the one Dru used, accurate knowledge of the location and its employees. But at a strange location, I would accept it from almost any employee. Even ones who I think are clearly wrong, like the recent Whataburger employees who told the off-duty police officers to leave because they were carrying. It isn't worth the risk to me.
...

Off duty LEO's are exempt from prosecution under 30.05 for carrying, but I suppose the Whataburger could kick them out for being cops...