Problems with not having ms windows when using webbrowsers in ubuntu

[user1]

I am using 12.04 and am constantly having problems with certain webpages 
in firefox mostly when paying with creditcards, even when using google 
chrome.

Some text get garbled during the creditcard payment procedure.

Also I have an internet bank, and am not able to get a digital signature 
because I am using ubuntu linux.

Seems like most banks are using ms windows.

I am not using windows and therefore not using wine.

Any suggestions?