hi, actually this little bit weird question but i just want to know about this. i worked lots of wordpress and joomla open source website and frequently those get updated version. is that updation going to affect my website SEO currently i have one joomla best website which is have joomla 1.5 version but now its need to be upgrade to joomla 2.5 is it this updation going to affect my joomla site SEO.
I don't think it will effect your SEO. Upgrading your software to the latest version give you more security and functionality. Actually it will help you in SEO as it will give more functionality.