Qezo,
Not sure, actually. We can see the same issue of no login button in IE8. The problem looks to be caused by some javascript errors on the page. They aren't being reported in IE, but in Firefox, even with the button, I can't log in. When the page first loads, I see the following 2 javascript errors:
Error: styles.match(/opacity:\s*(\d?\.?\d*)/) is null
Source File:
www.adoptapagan.com/plugins/content/mos_...tbox/js/prototype.js
Line: 1916
Error: $$.shared is undefined
Source File:
www.adoptapagan.com/cache/js-d60ef8b4c7d...6f63fa6fa7ba8d17.php
Line: 58
I'm not sure if they're both caused by the same plugin, but the mos_jdownloads_file seems to be the first error-thrower. You may want to try disabling this plugin (temporarily) to see if it fixes the issue. If so, let us know and we'll see what we can do to help. From it's name, I'm assuming it's a Joomla 1.0 plugin, which hopefully has a Joomla 1.5 native version available.