To reproduce:

• create a dialog with 3+ fckEditor instances
• the fckEditor instances must not be on the first tab (on the first tab they work fine)
• (For example edit the textImage dialog - copy the text tab, and copy the text field twice in that tab.)
• provide a content via that dialog
• reedit that content -> you should find only first fckEditor to render its value, others are empty. Resizing the dialog manually should supply the missing values also to other fckEditor fields.

This issue is not reproducible with ckEdit control, so as the 5.x based rich text fields.

Firefox versions tested:

• 33.1.1 at Windows 7
• 29.0 at Ubuntu 12.10