I won't pretend to be an expert on this, but I did not think jammers had that long of a range.

I would strongly suspect the cell phone provider/their partners.

For instance, in Baltimore, with Cingular, my cell phone was showing a full (4 bars, I think) signal strength, but I continually got dropped calls. I talked to a Cingular tech rep, which got me nowhere except for this bit of info...sometimes the cellular companies subcontract or whatever, their lines to others...even though those "others" go under the same business name. And, their networks are not seamlessly compatible with the other network provided by that same company.

I was taking a taxi once from BWi to downtown Batltimore, and the taxi driver had a cell phone with the same provide...Cingular. I asked him about this, and he said he'd never had a problem with them there.

Yeah, I was confused by this, too, but solved the prob by dropping Cingluar for another provider that would provide service when in their area.

Crazy stuff...