Change pagestyle to plain for first page of an unnumbered chapter

Change pagestyle to plain for first page of an unnumbered chapter

I'm writing my undergrad senior-thesis (at a German university) with the
following specifications:
\documentclass[12pt,headsepline,footsepline]{scrreprt}
\usepackage{fancyhdr}
\pagestyle{fancy}
\renewcommand{\chaptermark}[1]{ \markboth{#1}{} }
\renewcommand{\sectionmark}[1]{ \markright{#1}{} }
\fancyhead[LO]{}
\fancyhead[RE]{\thechapter}
\usepackage{apacite}
...
\begin{document}
\begin{titlepage}...\end{titlepage}
\pagenumbering{roman}
\tableofcontents
\listoffigures
\listoftables
\chapter*{List of Abbreviations}
\addcontentsline{toc}{chapter}{List of Abbreviations}
...
\chapter*{Abstract}
\addcontentsline{toc}{chapter}{Abstract}
\chapter{Introduction}
\setcounter{page}{1}
\pagenumbering{arabic}
...
...
\bibliographystyle{apacite}
\bibliography{references}
Almost everything is working now, only one problem remains: the "list of
figures" and "list of tables" chapters use pagestyle plain and appear in
the TOC; however, the list of abbreviations (which I created with
\chapter* because I don't want it to be numbered) uses the full header
both on the first and the second page (which is not perfect but
acceptable), plus it puts "LIST OF TABLES" in the header, i.e. the wrong
name and in capital letters, even though all the other chapter-names in
the headers are written in small letters (thanx to the
\renewcommand{\chaptermark}[1]{ \markboth{#1}{} }
\renewcommand{\sectionmark}[1]{ \markright{#1}{} } commands). Also, for
the references chapter, which is created automatically by the
apacite-package, the word "REFERENCES" in the header is written in capital
letters. Does anyone know how I can change those two things?