Shipping estimator not highlighting cheapest?

From what I understand, the shipping estimator should highlight the cheapest shipping method in bold. In the site I'm working on right now, no matter what the cost of shipping is, it's bolding the UPS option, which is usually not the cheapest.

The checkout process is correctly selecting the cheapest as the auto checked selection, so I know somewhere it's catching the cheapest right.

I'm running 1.3.0.1... is there some configuration item somewhere I'm missing or do I actually have a bug situation on my hands? I've tried everything I can think of.

is it highlighting by the sort order?

It doesn't appear to be, no. No matter where I have UPS set in the sort order, it's the one that's highlighted in bold.

The only shipping modules I've got installed are Store Pickup, UPS, and USPS. If I disable UPS, then USPS is always highlighted, even though I'm using a local address that is shown the store pickup option, which is free, so it's obviously cheaper than the USPS option.

I'm stumped.

Curiouser and curiouser... it seems to be highlighting whatever shipping module was activated last!

Argh.

I've just disabled then re-enabled UPS, and now USPS is always highlighted, regardless of which option is the cheapest.

Is there a way I can disable the highlighting on the estimator without sacrificing having it auto-select the cheapest option on check out? I don't really want it to highlight a method on the shipping estimator anyway...

I've tried commenting out the lines in shipping_estimator.php as suggested in this topic - http://www.zen-cart.com/forum/showthread.php?t=12045 - but that doesn't seem to make any difference at all.

It highlights the cheapest but not Store Pickup ...

Then, once one has been selected that is the one it knows the customer said they wanted so it remembers until another is chosen ...

Ok, that seems to hold true... thanks! I thought I was losing my mind! :)