This was in the release notes for 1.5.2 which noted the things that will be fixed in 1.0.4 which includes things for Esplora:
ARDUINO 1.0.4 - Not yet released.
* Fixed malloc bug (Paul Stoffregen)
* Fixed memory leak when calling Ethernet.begin() multiple times.
* Fixed SD example listfiles.ino
* Fixed a lot of Esplora examples
* Sort entries in preferences.txt (Shigeru Kanemoto)
* Fixed some wrong translations
* Fixed NPE due to permissions IO error
* Updated drivers for Windows (all-in-one, signature for Win8)