I am currently using the Arduino software ver 1.0.1 (Windows) with an UNO R3 and the ethernet w5100 ethernet shield with sd card. The WebServer example in the 1.0.1 package appeared to work initially but I found it and other scripts to be intermitent over repetative usage with a web browser. After researching I found that I had to modify the example to add an additional line to set pin 4 high (digitalWrite(4,HIGH); ) in the setup and it now runs like a champ. Not sure why it was left out in the example.
I have a need for the webserver app to include SD functionality (read and write files). I have come across some examples but I believe they are old and do not compile with the 1.0.1 software. Can anyone point me in the right direction.