Hello,
I am running version 1.8 on Joomla 2.5.4. We recently started experiencing blank pages when we log in. I have it set to go to the members list after log in. I ran the tools and did have to do a fix on the database but it didn't help the issue. What is weird is that I turned on site debugging in Joomla and everything starts working perfectly. As soon as I turn debugging off, it starts giving me blank pages. I am at a loss as to the issue.