As I have exactly the same issue, ie. Apache thread crashing when I reach a breakpoint, could you post replies to the initial post in english (sorry, I don't understand german). My configuration: Vista 32 bits Home Premium, Service Pack 2, XAMPP 1.7.3 default installation + xdebug enabling.
PHP 5.3.1 with "This program makes use of the Zend Scripting Language Engine: Zend Engine v2.3.0, Copyright (c) 1998-2009 Zend Technologies
with Xdebug v2.0.6-dev, Copyright (c) 2002-2009, by Derick Rethans" from phpinfo() menu in apache admin.
xdebug
xdebug support enabled
Version 2.0.6-dev
Supported protocols Revision
DBGp - Common DeBuGger Protocol $Revision: 1.125.2.7 $
GDB - GNU Debugger protocol $Revision: 1.87.2.1 $
PHP3 - PHP 3 Debugger protocol $Revision: 1.22 $
Directive Local Value Master Value
xdebug.auto_trace Off Off
xdebug.collect_includes On On
xdebug.collect_params 0 0
xdebug.collect_return Off Off
xdebug.collect_vars Off Off
xdebug.default_enable On On
xdebug.dump.COOKIE no value no value
xdebug.dump.ENV no value no value
xdebug.dump.FILES no value no value
xdebug.dump.GET no value no value
xdebug.dump.POST no value no value
xdebug.dump.REQUEST no value no value
xdebug.dump.SERVER no value no value
xdebug.dump.SESSION no value no value
xdebug.dump_globals On On
xdebug.dump_once On On
xdebug.dump_undefined Off Off
xdebug.extended_info On On
xdebug.idekey nous no value
xdebug.manual_url
http://www.php.net http://www.php.net xdebug.max_nesting_level 100 100
xdebug.profiler_aggregate Off Off
xdebug.profiler_append Off Off
xdebug.profiler_enable Off Off
xdebug.profiler_enable_trigger Off Off
xdebug.profiler_output_dir C:\xampp-173\xampp\tmp C:\xampp-173\xampp\tmp
xdebug.profiler_output_name xdebug_profile.%p xdebug_profile.%p
xdebug.remote_autostart On On
xdebug.remote_enable On On
xdebug.remote_handler dbgp dbgp
xdebug.remote_host localhost localhost
xdebug.remote_log no value no value
xdebug.remote_mode req req
xdebug.remote_port 9000 9000
xdebug.show_exception_trace Off Off
xdebug.show_local_vars Off Off
xdebug.show_mem_delta Off Off
xdebug.trace_format 0 0
xdebug.trace_options 0 0
xdebug.trace_output_dir C:\xampp-173\xampp\tmp C:\xampp-173\xampp\tmp
xdebug.trace_output_name trace.%c trace.%c
xdebug.var_display_max_children 128 128
xdebug.var_display_max_data 512 512
xdebug.var_display_max_depth 3 3
Debug Client: Netbeans 6.8
Thanks for your help
Just want to add that with XAMPP 1.7.0 and php_xdebug-2.0.0-5.2.2.dll, it works perfectly on same OS.