Huge problem: after 'I confirm my order' nothing happens

[salko]

I opened my shop about 10 days ago and I already received a complains from two different customers, both telling me that after clicking 'I confirm my order' nothing happens, so they cannot place an order ... I already received several orders with no problem, also yesterday I made a test purchase which went through with no problems. So what could be the case here?? Maybe some kind of uncompatibility with customers web-browsers or what?? This is very annoying problem and god knows how many customers did not place an order because they could not do it ... Please help!

[salko]

Now I have few more details from one customer with this problem:
- customer is using Internet explorer 8 (ver. 8.0.7600.16385), she also tried with Google Chrome with no luck
- customer choosed 'bank wire' payment option
- after the click on `I confirm my order` she waited for 3 minutes and then she tried again with no luck

Then I have placed an order using her user account and using same 'bank wire' payment option and I have placed order with no problems, using Firefox. After clicking on 'I confirm my order' it takes about 5-10 seconds to receive this order-return page. Is this normal or this suposed to be faster? Thank you for any help!