Depending on zoom level, spaces in underlined texts trigger added line thickness, sometimes above, sometimes below the regular line.
	This looks like a spurious underline character and therefore is of more than just cosmetic relevance
	
	The problem seems to be limited to screen rendering, if saved as pdf, the underline is of constant thickness:
	
	SMath Studio: SMath Studio Desktop 0.99.6611.22150, x64
	OS: Microsoft Windows NT 6.1.7601 Service Pack 1 (Windows 7 Professional Service Pack 1, x64)
	Screen: 1920x1080 px, 96x96 dpi, 96 GP.DPI, 1 GP.SRF
	Localization: separator=<semicolon>; decimal symbol=<comma>; system decimal symbol=<comma>; language=ENG
	Frameworks: CLR 4.0.30319.42000
	
	    installed versions:
	    v2.0.50727    2.0.50727.5420 SP2
	    v3.0    3.0.30729.5420 SP2
	    v3.5    3.5.30729.5420 SP1
	    v4    
	        Client    4.7.02053
	        Full    4.7.02053
	    v4.0    
	        Client    4.0.0.0