gb4e leaves extra (unwanted) blank line space between gloss and translation. Same problem as here: Why is the gap between the translation and the last line of the gloss so wide in my interlinear gloss? but the answer there (cgloss.sty) doesn't always fix the problem. In the following code - the third \glt line has a wide space before it:
\documentclass{article}
\usepackage[safe]{tipa}
\usepackage{gb4e,cgloss}
\begin{document}
\begin{exe}
\ex \gll kma t'-\textschwa{l}\v{c}qu-(\textgamma)in \\
{\sc 1sg} {\sc 1sg.sub-}see-{\sc 2sg.obj} \\
\glt `I saw you.' (S1:71)
\ex \gll q-\textschwa{l}\v{c}qu-{\textbeta}um kma\\
{\sc 2.irr-}see-{\sc 1sg.obj} {\sc 1sg}\\
\glt `Look (at) me.' (S1:75)
\ex kma t-k'o{\textbeltl}-ki\v{c}en \\
{\sc 1sg} {\sc 1sg.subj-}come-{\sc 1sg.subj} \\
\glt `I came/arrived.' (S3:13)
\end{exe}
\end{document}

\scwith\textscand clean up the code a bit. – Sverre Jun 14 '14 at 18:21