I've discovered this is a Mac issue as it is working fine on PC. Does anyone have the slightest idea?

I have tried this in my MacBook Pro using the following URL:

http://www.alkhater.net/en_blog/sel_stub.php/2007/01/05/p977#more977

I used a simple text tag not a button and it works just fine

You can see it in action if you go to:

http://www.alkhater.net/en_blog and click on the Test link near the top of the sidebar.

I tried it and it works with Safari and Firefox.

I notice in your message that you missed "www" in your second URL. Maybe that is why, I'm only guessing.

I'll leave it for a day, hope thsi help

The missing "www" is not the problem. I tested the link without it and it works.

By the way I'm using ver. 1.9.1 beta. Which version are using?