Product Version = NetBeans IDE 7.1 Beta (Build 201109252201)
Operating System = Linux version 2.6.38-11-generic running on amd64
Java; VM; Vendor = 1.7.0_02-ea
Runtime = Java HotSpot(TM) 64-Bit Server VM 22.0-b06
Opening a text file, and whatever typed from keyboard, nothing is written on the file. Copy and Paste works though.
Can you try new dev version? It definitely works on my dev version:
Product Version: NetBeans IDE Dev (Build 201110020601)
Java: 1.6.0_26; Java HotSpot(TM) 64-Bit Server VM 20.1-b02
System: Linux version 2.6.38-11-generic running on amd64; UTF-8; en_US (nb)
I created new empty file, named it test.txt and I could write, save etc.
I opened test2.txt where was some text and I could edit, write, etc.
So please try newer dev version, and if it is still not working, describe how you open file.