We have quite a unique problem. We have a huge project with a collection of SWC's, all compiled with the Flex SDK 3.2. One of the libraries reference an old beta version of textLayout.swc.
I imported my large project into Flash Builder and got dozens of compile errors, relating to the text-layout libraries, eg. "Type was not found or was not a compile-time constant: ContentElemenet". After creating a test project I was able to deduce that the compile errors were due to the library referencing textLayout.swc
I managed to get my project to compile and run by recompiling the library that referenced textLayout.swc, compiling it with the Flex 4 SDK running in Flex 3 compatibility mode and removing the textLayout.swc reference. I had to recompile my large project with the Flex 4 SDK + Flex 3 compatible mode as well and everything seems to work fine, after a few minor tweaks (eg. remove paddingTop references from Canvas elements)
The only problem I am having is that it's added an extra 2MB to my already large 4MB compiled (debug, not release) size.
I assume this is because it has to include the new Flex 4 SDK libraries + possibly Flex 3 backward compatible components.
I assume this would not be the case if I was able to compile the project in Flash Builder with the Flex 3.2 SDK. Theoretically it should all work the same with the default SDK set to Flex 3.2 (copied from my Flex Buider 3 app directory). Why does this configuration not work when I reference textLayout.swc - especially if compiling under 3.2 should not result in any references from Flex 4 SDK to be pulled in. Is there anything I can do to make it compile under the 3.2 SDK, so that I can keep my file size under 5MB?