Flash Builder keeps losing my imported classes...arghh

I've been having this re开发者_如何学JAVAally annoying thing happen the past few days, that has happened before but not as frequently. I create a project in Flash Builder, import some classes, and then on occasion it keeps erasing those classes. So then I get errors in a lot of my datatypes, have to go back through my document and retype the datatype so that it reimports the class.

What could be causing this? I know flash builder can be a bit buggy at times, but wasn't sure if someone else has had this problem and knows what might be causing it.

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I haven't worked that much with flash builder yet, but I have had it clean up unused imports for me rather unexpectedly when I'm refactoring code. i.e cut a section of code from one section - flash builder cleans up imports - then when I paste the code back somewhere else, I'm missing the necessary imports.

I think if you go to: Window > Preferences > Flash Builder > Editors > ActionScript

You can disable "remove unused imports" and see if this fixes your problem.

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This was a known bug in the FB4 betas. Make sure you are using the release version of FB4.