I'm seeing the same thing with B5 running on RHEL v6.5 on a VMware v6.0.4 virtual machine running on Mac OSX 10.9.5
To reproduce just grab a document tab and drag it off the tab bar and poof everything between the toolbar and status bar goes away. If I drag the tab outside the bounds of the original document area, everything returns as normal - full color, not grayed. Drag it back and poof gone again. If while dragging, I hover the mouse pointer over the divider between existing documents in the split view, everything draws again, and disappears when I move the mouse. Once the mouse is released, everything draws and is fine.
The Mac version works as expected (although I'm not sure I like the grayed out background).
-Tim
SlickEdit 2014 (v19.0.0.8 64-bit)
Serial number: FE56917_BETA
License type: Beta License
License expiration: 2014-11-02 02:36:00
License file: /opt/slickedit/bin/slickedit.lic
Build Date: September 16, 2014
Emulation: CUA
OS: Linux
OS Version: Red Hat Enterprise Linux Workstation release 6.5 (Santiago)
Kernel Level: 2.6.32-431.29.2.el6.x86_64
Build Version: #1 SMP Sun Jul 27 15:55:46 EDT 2014
Processor Architecture: x86_64
X Server Vendor: Red Hat, Inc.
Memory: 33% Load, 4874MB/14632MB Virtual
Shell Info: /bin/csh -i
Screen Size: 2556 x 1363
Project Type: Verilog: Model Technology ModelSim
Language: .v (Verilog)
Installation Directory: /opt/slickedit/