# Escape code \"{u} for umlaut gives Runaway argument? error

I'm using the escape code \"{u} in my .bib file to indicate umlauted 'ü'. When I compile my document, however, I get the following error:

Runaway argument?
{Phonetische studien. Zeitschrift f\}. \par \end {thebibliography}
! File ended while scanning use of \emph .


Where the umlaut 'ü' is supposed to be in 'Zeitschrift für ...'.

Other espace codes work fine, however, such as \'{u} for ù. I assume it has something to do with the preamble of my main document, but I have no idea how to figure out how to fix it (googling didn't help). Here's my preamble:

\documentclass[letterpaper, 12pt, onecolumn, notitlepage]{article}
\usepackage[margin = 1in]{geometry} % set margins
\pagestyle{myheadings} % page numbers in top right corner
\linespread{1.6} % double spacing throughout the document
\usepackage[hang, flushmargin]{footmisc} % no indent in footnotes
\usepackage{lmodern} % font
\usepackage{linguex} % for \ex. (numbered examples)
\usepackage{tipa} % for \textipa (IPA symbols)
\usepackage[normalem]{ulem} % for \uline
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\renewcommand{\textipa}[1]{{\fontencoding{T3}\fontfamily{cmr}\selectfont#1}} % this prevents the \textipa command from trying to employ lmodern (which it cannot do). The effect is only that a warning message about it won't appear.
\usepackage{natbib} % package for bibliography
\bibpunct{}{}{,}{a}{}{,} % punctuation for citations
\date{} % date is not printed with title

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How about using {\"u} instead of \"{u}?
@Sverre: Just \"u also works, too. – Ryan Reich Nov 21 '11 at 6:58
@RyanReich With \"u there can be problems with the sorting process, that are avoided with {\"u} or {\"{u}} – egreg Nov 21 '11 at 9:56