Cross browser CSS glitch / problem with exactly the same code

Hi my name is Peter and have a CSS cross browser problem which is giving a HUGE headache. Please forgive me if his is in the wrong category. I am totally out of options :'(
Hopefully someone of you can help me…

I am running wordpress site with a thesis framework and a custom skin.
This is the CCS code in my custom CCS:

.custom .testvb
{border:1px dotted black;
padding-left:1em;padding-top:1em;padding-right:1em;padding-bottom:1em;
background-color:#c5ebfb;
background-image:url(‘http://www.fibonicci.com/images/gradients/gradient-5×300.jpg’);
background-repeat:x;
background-position:center;”}

I copied/pasted .testvb code and added a “c” to make .testvbc

.custom .testvbc
{border:1px dotted black;
padding-left:1em;padding-top:1em;padding-right:1em;padding-bottom:1em;
background-color:#c5ebfb;
background-image:url(‘http://www.fibonicci.com/images/gradients/gradient-5×300.jpg’);
background-repeat:x;
background-position:center;”}

The code is exactly the same and both CSS codes work in Chrome, but the 2nd code does not work in Internet explorer or Firefox… WTF! :S

<div class=”testvb”> Hello, please help </div> Works in all browsers
<div class=”testvbc”> Hello, please help </div> Does not work in IE or Firefox :S

http://www.fibonicci.com/nl/css-problem

How is this possible????
I have switched off auto cache. I have tried several names for the div class. I can do what I want, but the only code that works is the ‘original’ .testvb. Can anyone tell me if its just my IE or Firefox or that you also cant see the 2nd box…

Does anyone have any clue? Because this goes way beyond my understanding of anything :S