I have been using the new Beta version and love the resize demo, which I'm going to implement on a website right now.
However I came across a problem which might drive some others insane, so here's the info!
I ran the demo on my linux server and it worked perfect, however a client's machine wouldn't get the POST "Filedata". It would return a string 4 chars long...
I checked everything from the code to PHP settings and even Apache. To no avail. In the end it turned out to be an issue with the version of PHP they were running.
It seems PHP version 5.1.6 causes this bug, and upgrading to 5.2.12 solved the problem straight away.
I hope this helps someone 
Glenn
February 12, 2010 - 10:51am
This is probably due to NULL bytes in the image data. It is tricky. Many of the functions (like echo) will only display up to the first null. But if you fwrite the data to a file or check the length it will show all the data.
The PHP bug tracker reports issues with null bytes but it is hard to determine which versions are affected and when the problems were fixed.
February 12, 2010 - 12:50pm
I tried writing it to a file using fwrite but got an empty file. The data was simply not there... all very strange.