If you use the CLI you will be able to see what versions of firmware are installed. I would suggest the following commands in a Netvata:
ADTRAN, Inc. OS version R11.2.0
Mainline Version: ENM.14.50
P4 Changelist: 144527
Built on: Tue Jun 3 18:31:07 2014
Upgrade key: ff549de56bb61089de28fa0b974d95a0
Boot ROM version XB.01.02
Built on: Fri May 25 16:51:16 2012
Copyright (c) 1999-2014, ADTRAN, Inc.
Platform: NetVanta 1234 PoE, part number 1702595G1
Serial number LBADTN1332AE156
Flash: 33554432 bytes DRAM: 134217727 bytes
xxxxxxxxxxxxxxx uptime is 1 weeks, 4 days, 3 hours, 36 minutes, 8 seconds
System returned to ROM by Other
Current system image file is "N123Xv2A-R11-2-0.biz"
Boot system image file is "N123Xv2A-R11-2-0.biz"
Primary system configuration file is "startup-config"
There is also "dir" (Much like a directory command on a PC it shows the contents of the flash drive)
13591421 bytes used, 18048994 available, 31640415 total
Look for the oldest or unused and delete. I hope this helps
No problem. CLI has many more abilities than the GUI from a configuration and engineering perspective.