Something goes very wrong during checkout

[ngruy]

Hi,
I receive comments from my clients (more & more often) that they can´t shopping because in the checkout process they are stuck in order step 1, when they click “continue”, nothing happened.

If they change “https://ww......../order.php?step=1 “ to “.../order.php?step=2” in the navigator bar, they can continue.

Please, any help would ve very ver apreciated, i don´t know how/where to start.
I can´t reproduce this error in my pc, but 5 of 10 customers have this problem.

PS 1.3.1.1

Thanks

[shokinro]

If this is not 100% happening issue, it is difficult to figure out and to fix.
I think first thing you need to do is to identify how the problem occurs.
For example, does it happen only when order some specific products? or it happens on specific browser type? browser setting and so on. (Just some thoughts)

Once you know how to reproduce the problem, then turn on error message display at /config/config.inc.php by set 'display_error' to 'on'. Error message will be displayed on the top of your page.

[ngruy]

Thanks for the tips, i still can´t fix this and can´t reproduce the problem. But i get everyday 2 or 3 clients with this problem. I don´t know when does it happen, have clients with IE, firefox, chrome and opera (win xp, 7, vista) add in his baskets different products and same problem.
People make this steps.
1 - Add a product
2- register an account
3- Try to add a shipping address and here they stuck,they can´t add a new address.
4- back to step 1, trying to continue with the wrong shipping address and they can´t...continue button don´t work and no error was shown. Generally they leave the site and never come back, in some cases they call us or send an email.

[shokinro]

Not sure, but I guess the issue seems related to shipping address (country/region/state/) settings.
Check if the errors only happens with customer from specific country or region?