I am not Ricky but would like to mention that when pressing the key, the focus perhaps had momentarily shifted to a textbox input and zooming brings it back to the graphics area where the geometry is being attached. Check if you are able to see any input box on the command bar or somewhere on the screen having one or more 'e' letters in it.
Some process running in the background on you computer might pull the focus from Solid Edge ridding it of the current application status and then with a proactive zoom command you make SE the current application.
Also Auto Save if currently ON might not allow SE to respond to some user inputs like a key press though I am not very sure about this last guess. This setting is in the Solid Edge options box - Save tab. Try setting it OFF for sometime and observe it it helps.
Can you give specific steps to reproduce the problem. I cannot reproduce it with the limited information given. This is just a guess, but if I remember correctly, you use an input device like a space mouse. Is that correct? If you can reproduce the problem, please include specific directions including information about input through your input device. Input can go to two different directions. Those are (1)keyin fields or other UI or (2)graphic window input such as capturing 'e' to indicate endpoint. This is called dual focus. Solid Edge will typically push the input in the proper direction depending on conditions such as mouse position. Is the mouse over UI or is the mouse over the graphic window? There are other factors, but I will keep it simple. If you are using an input device, is it possible that the device is intercepting the typical flow of input causing Solid Edge to get confused about the nature of the input. Usually if an invalid input is sent to a keyin field such as a value, there will be a beep along with an error box stating that the input is invalid.
Ricky, I've delayed my response because I can't get the symptom to reproduce on command. It seems to happen at random. For example, if it happens once and than I UNDO to repeat it, it works OK.
Also you used some unfamiliar terms. Yes, I do use a gaming mouse with several commands programed into the multifunctional buttons on the mouse.