I tried the Linux 2.6.0 kernel and experienced a major slowdown of KMail when it tries to display a larger folder (~2-5k mails). It takes roughly 15 seconds under 2.6 but under 2 seconds under 2.4 (a rough estimation). The mail directory is on a ReiserFS (v3) partition. I guess it is somehow related to ReiserFS because when I copied the mails to an ext3 partition it worked better (but the test wasn't clean because I tried it directly after copying and perhaps the cache was filled with the correct data). Does anyone have an idea what the problem is?