[XAMPP] PEAR/PECL install failes

hi all,

I just tried to install memcache a pecl extension for php.
somehow it won't work..

Microsoft Windows XP [Version 5.1.2600]
E:\>pecl install memcache
downloading memcache-2.2.0.tgz ...
Starting to download memcache-2.2.0.tgz (24,745 bytes)
.........done: 24,745 bytes
8 source files, building

Warning: PEAR_Registry::require_once(System.php): failed to open stream: No such
 file or directory in R\PEAR\Registry.php on line 339

Fatal error: PEAR_Registry::require_once(): Failed opening required 'System.php'
 (include_path='\xampp\php\pear') in E:\xampp\php\PEAR\PEAR\Registry.php on line
 339

E:\>

if I set the include_path to (in this case) 'E:\xampp\php\pear' I will get a bit further which suggests to me that at least some part of this problem is portable-related.

Microsoft Windows XP [Version 5.1.2600]
E:\>pecl install memcache
downloading memcache-2.2.0.tgz ...
Starting to download memcache-2.2.0.tgz (24,745 bytes)
.........done: 24,745 bytes
8 source files, building
ERROR: The DSP memcache.dsp does not exist.

E:\>

google doesn't come up with anything on the last error message. and the pecl extension memcache-2.2.0.tgz is nowhere to be found. maybe here as well a missing drive letter is the cause?

any clues?

thanks a lot!
/christian