It sure could be Adblock. You should definitely try out Ublock and have a better experience than with Adblock. I personally don't trust Adblock anymore. And if you're on Yosemite you should check out Adguard as well. It's a content blocker and (in ways that were explained here before) more effective and resource friendly than the old Safari extensions. And to my knowledge it's the only one right now that is at least somehow customizable (whitelist, etc.).
Edit:
Btw. You mentioned you're using click2plugin, so I guess you are still having the Adobe Flash plugin installed. Flash hasn't been a good experience for me (and a lot of others) and I got rid of the plugin a long time ago. You should try living without it, especially for security reasons. There are only a few sites left that require Adobe Flash installed and if that's the case, Google Chrome is a good fallback option to browse these sites. Uninstall the Flash Plugin and try browsing without it for a few days. I'm pretty sure you're not going to miss it.