Hi Joeri. Due to Android 2.1's rapidly vanishing device share (< 6%):
Android 2.1 was never officially supported for Sencha Touch 2. We did a lot of work to make 2.2 and 2.3 fast, but nothing for 2.1. Note that we do need a minimum amount of horsepower to make Android work well, and we've seen some freebie Androids that just don't have the chip power to push screen bits around. The errr.. "good news" is that native Android apps are also pretty terrible on those platforms.