Errors are (seemingly) cached for several minutes whilst no cache is turned on within CI

[eluser]Jailbird[/eluser]
This happens only with Codeigniter 2.0+, and I've recreated the phenomenon on several different server-configs.
When an error happens (PHP or Db) and I fix the problematic part, the error-message stays there for several minutes. A simple refresh wont help. No cache (web or Db) is turned on within Codeigniter. I'm either forced to wait for several minutes or I temporarily change the method name and access the controller that way to see the fixed part.
Anyone have a clue what's causing this? Thanks for your help in advance!

[eluser]CrossMotion[/eluser]
Just a wide guess, but maybe your web server or PHP have some kind of caching mechanism enabled?

[eluser]Jailbird[/eluser]
I have thought about that, but this symptom recurs on at least 5 different servers (LAMP/WAMP, different configs). Non-CI code or CI 1.7 works fine on all those, so I assume it's not the servers' cache mechanism what is causing the problem, yet something in CI 2.0+. But can't tell for sure.

[eluser]CrossMotion[/eluser]
In that case I have no idea. As far as I know CodeIgniter can only cache pages if you explicitly tell it to in the controller, but you can check the application/cache folder to be sure.