Please, enter your e-mail, so we could answer you.
Then type your message and press “Send”.
We’ll answer shortly.
Unfortunately the update that was made to speed up the rendering has lead to an opposite result on iPhone 4, iPod 4 and earlier devices. A technique of caching drawing into pre rendered images normally works much faster than drawing vector and text on each screen update, but as it turns out on the affected devices it does work much slower instead. The urgent bug fix is in the works now and will be released as soon as possible.
Until the update arrives, please, use the temporary workaround – double tap on the main screen for the quick switching menu and turn off maps and camera. The maps and camera are primary CPU and battery power consumers – turn them off and it should do the thing for now. You still can use maps for anything except the main screen without the performance loss – to add, edit and to show waypoints.
In case the lag stays with maps and camera off it means the system runs low on free memory. The system tells the app to free memory and thus it flushes all the image cache and then rebuilds at least a part of it again immediately – what may be CPU consuming. To overcome this and to free system memory you can perform a cold iOS reboot – tap and hold POWER and HOME buttons simultaneously until a white apple appears, then release both buttons.