HELP - Orders Monetary Value over £500 Sends Browser into Continuous Loop

I've just noticed that whenever my shopping cart goes over £500, it sends the browser into a continuous loop and it doesn't know how to process to ceheckout. In Firefox, I get this:

***The page isn't redirecting properly

Firefox has detected that the server is redirecting the request for this address in a way that will never complete.

*   This problem can sometimes be caused by disabling or refusing to accept
      cookies.***

I remember I had a similar problem a few months back with weight. Last time, it was because my shipping modules weren't configured to handle anything over a certain weight. As soon as I told the shipping modules that I can process orders over 100kg, it was fine.

What can be causing this now though, with the monetary value? As soon as it goes over £500, it just goes into a continuous loop.

It's doing this on two of my sites:

https://www.silkblooms.co.uk
https://www.superfancy.co.uk

There must be more to this ...

My test:

10 Turquoise Blue Ivory Wedding Flowers,Aqua Wedding Bridal Shower £549.90

I followed the process right through to just before confirming payment (both paypal and google checkout. No sign of any problem

Cheers
Rod

Thanks for testing Rod, but I should have been more specific.

PayPal Express and Google Checkout are working fine, it's the normal checkout. If you click the 'pay by credit or debit card' button instead of the PayPal or GC buttons, then log in. It won't go to the checkout page.

I have another site using an almost identical template, which works perfectly, even when cart goes well over £500000...... So, I've been trying to copy files from the working site over the faulty sites, to see if I can at least determine which directory of files is causing this.

I've tried four full folders so far, but none of these filesets are responsible (the browser still loops even when the working sites files are in these folders):

/includes/modules/payment
/includes/modules/shipping
/includes/templates/CUSTOM/templates
/includes/templates/CUSTOM/common/

Does anyone with more Zen Cart experience have a better idea which directory of files is likely to contain the culprit?

Update, I've now replaced all of files in the following folders (from a working template) and it's still not working (obviously didn't replace configure.php):

/includes/modules/payment
/includes/modules/shipping
/includes/templates/CUSTOM/templates
/includes/templates/CUSTOM/common/
/includes/modules/order_total
/includes/modules/sideboxes
/includes/templates/CUSTOM/sideboxes

Does anyone with more Zen Cart experience have a better idea which directory of files is likely to contain the culprit? Could it be an admin file that's causing this??

Have now totally replaced all of these:

/includes/modules/payment
/includes/modules/shipping
/includes/templates/CUSTOM/templates
/includes/templates/CUSTOM/common/
/includes/modules/order_total
/includes/modules/sideboxes
/includes/templates/CUSTOM/sideboxes
/includes/modules/pages
/includes/auto_loaders
/includes/classes

Pretty scunnered with it. I've no idea what file or even directory could be causing this.

limelites:

Thanks for testing Rod, but I should have been more specific.

It would help :-)

limelites:

PayPal Express and Google Checkout are working fine, it's the normal checkout. If you click the 'pay by credit or debit card' button instead of the PayPal or GC buttons, then log in. It won't go to the checkout page.

I wasn't able to duplicate your looping problem, but I did observe that your Nochex payment system does appear to have a limit on the $amount that it will allow to be processed without an account...

My test purchase over $500 produced this message:

"Either the amount you are trying to send exceeds the recipients receive limit or the recipient is not enabled to receive payments from non members of Nochex".

A test puchase of around $200 worked just fine.

Cheers
Rod

I'm aware of the Nochex payment limit. It's currently set at £500 dead.

I managed to figure this out late last night but was too tired to post the solution. I feel like a numbskull as it was a setting in admin/modules.php?set=shipping&module=specialdelivery

There's a sneaky little "Maximum order vallue" in there and I didn't notice it at first. It's set to £500 by default, so I just increased it. One to watch out for in future as I don't use table rate shipping.