[Gimp-user] Lagging when initially selecting Levels/Thresholds/Curves

[Andrew Clarke <clarke_andrew btinternet com>]

Hi, I am using the below:

Simone Karin Lehmann bulid - Mac OS X 10.9.x Mavericks & Yosemite - 
2.8.14 *** new 01.02.2015 ***

MacBook Pro 2.9Ghz i7 8GB ram SSD drive - OS X Yosemite

I have an open image, when initially selecting one of these tools there 
is a lag of about 10-15 seconds before the window will open to make 
adjustments, and then onwards they load straight away.
If I then make a copy of that layer, I again get a lag before the window 
opens, and then again onwards opens as expected. If I then copy the 
layer again, I again get the same behavior.
Is this expected behavior ?
Kind regards
Andrew