Just to make sure there was not something wrong with my project that was causing this problem, I created a new workspace and project from scratch. The attached zip file contains that workspace, and it exhibits the same delay problem.
Below is the info on my configuration. Let me know if you want me to send any other files.
SlickEdit Pro 2015 (v20.0.0.10 64-bit)
Serial number: FE25543_BETA
License type: Beta License
License expiration: 2015-12-10 03:04:00
License file: C:\ProgramData\slickedit\20\slickedit.lic
Build Date: October 29, 2015
Emulation: CUA
OS: Windows 8 x64
OS Version: 6.02.9200
Memory: 33% Load, 8172MB/24455MB Physical, 9374MB/28039MB Page File, 718MB/134217727MB Virtual
Shell Information: C:\WINDOWS\system32\cmd.exe /q
Screen Size: 1920 x 1080, 1440 x 810, 1920 x 1200
Project Type: Cpp
Language: .h (C/C++)
Encoding: Automatic