Arabic text is detached I have these two issues. The text is detached in tweetcaster. Along with being detached, in the browser, the reading order is wrong. 

I hope upgrading the current pre installed browser or installing a separate one would solve browser trouble. But how about tweetcaster? What is the fix for that? If there is no fix except wait for upgrade, could you please suggest a Twitter client that displays Arabic text properly? 

I have HTC desire running android 2.1.
You can try the browsers that don't use the internal WebKit rendering engine, i.e. Opera Mobile, Firefox, Opera Mini or SkyFire. For Android 2.2 there's also Persian Browser which uses WebKit and connects the letters after loading the page.