Error fetching rectangles

I get a bad behaviuor on a mobile project, tested on a Galaxy Tab tablet.
my project is composed by a large number of pages and templates. it’s very slow on the launching stage (from the login to the window displaying) and sometimes it gets me the “Error fetching rectangles” on changing windows.

so i started the task monitor on the server and i see 100% CPU spikes on windows changing events, that last for 5-7 secs… note that it takes 20 seconds to see the new page from the click moment.
i made another test launching the same project with a normal Java client: the behaviour is the same (it’s very slow) but i get no cpu spikes (is the PNG rendering so heavy?).

what’s the problem? have i to tune Java parameters?
what kind of diagnostic can i do?

thank you

thinking about releasing the project, i think i need at least the tablet screen notifying the user to wait some seconds.
in the desktop application we have the loading spinning round on changing window.
this feature is not present with the mobile module. is there an alternative way to make the project more user friendly?

The mobile be getting some polish work and usability work done on it soon. Possibly around the 7.7 timeframe but I can’t be certain. The error fetching rectangles issue will hopefully be addressed when this happens.