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Issues with Screengrab and Firefox 3.6
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Screengrab 0.96.2 has an issue with Firefox 3.6, where it calls the deprecated getBoxObjectFor function when locating Flash or Java objects for capture. This makes it silently fail. This is fixed in 0.96.3 (currently waiting for approval from addons.mozilla.org).
Issues with Screengrab and Firefox 3.5
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Screengrab 0.96.1 has an issue with Firefox 3.5 where some shots will come out with a black background. 0.96.2 fixes the issue.
https://addons.mozilla.org/en-US/firefox/downloads/file/59229/screengrab-0.96.2-fx.xpi
Issues with Flash or Applets (Java 6u10/6u11 & Screengrab! 0.96)
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Due to an issue with the new Java Plugin in 6u10 and 6u11, Screengrab 0.96 will fail silently while attempting to capture any page with Flash or Applets in it.
To fix this, please upgrade Java to 6u12 or above.
Screengrab! 0.96.1 addresses this issue by acting as though Java is disabled if it finds either of these two versions.