Good news!

Thomas Mittet has now fixed his excellent X10ex library which can be found at http://code.google.com/p/arduino-x10/downloads/list

The problem was caused by changes to the Serial communications introduced with Arduino 1.0, especially the behavior of the "Serial.flush()" command.

As I write this I dont know if the other X10 libraries have been fixed.

I've been in touch with Tom Igoe who wrote the original X10 receive code.  He has now modified it to work with 1.0.1 (arduino.h and wire library mods), it compiles but unfortunately it doesn't work for me. I live in the UK (50Hz) and he is in 60Hz land and doesn't have any X10 kit to test it with - can anyone help?
The new code is at https://github.com/tigoe/x10

Meanwhile I'm trying other routes.
X10ex from http://load-8-1.blogspot.com/2010_06_01_archive.html also works OK with 0.22 but fails with 1.0.1.  It looks like a timing issue as the commands are received by the arduino, indicating the interrupt is OK but they are being interpreted with the wrong house code and value. I've emailed the author and am waiting a reply.

I've done a bit more digging and found that that the standard X10 Library also stops working when compiled with 1.0.1 but is OK with alpha 22 and 1.0.

Since upgrading from Arduino 1.0 to Arduino 1.0.1 the x10ex and standard X10 libraries have stopped working.  
The example sketches X10_Serial from x10ex and X10_receive from the standard library will neither send nor receive with 1.0.1.  

I needed to change WProgram.h to arduino.h in the library to make it compile, otherwise the sketch is unchanged.  

#if ARDUINO >= 100
#include <Arduino.h>
#else
#include <WProgram.h>
#endif

The rewind fixed it - thanks

Thanks for looking at this, code in the webduino handler is cut and pasted from the example with a change to variable names viz;

Code:

if (!sd.init(SPI_FULL_SPEED, chipSelect)) fatalError("SD init error");
...

while (myFile.openNext(sd.vwd(), O_READ)) {
    myFile.getFilename(name);
    cout << name << endl;
    myFile.close();
  }

...

Files are all YYYYMMDD.LOG or ALPARMS.TXT, some of the .LOG files are missing as is ALPARMS.TXT and I'm using the latest SDFAT code (Sept 2nd 2011).

I worked around it with the following which works fine;

Code:

...
   if (!card.init(SPI_FULL_SPEED, chipSelect)) fatalError("SD init error");
   if (!volume.init(&card)) fatalError("vol.init failed!");
   if (!root.openRoot(&volume)) fatalError("openRoot failed");
...

  while (root.readDir(p) >0) {       
    if (p.name[0] == DIR_NAME_FREE) break; 
    if (p.name[0] == DIR_NAME_DELETED || p.name[0] == '.') continue;     
    if (!DIR_IS_FILE_OR_SUBDIR(&p)) continue; 
    nameS = "";
    for (uint8_t i = 0; i < 11; i++) {
      if (p.name[i] == ' ') continue;
      if (i == 8) {
        nameS += '.';
      }
      nameS += String(p.name[i]);
    }   
    Serial.print(nameS);
...
 
  }

This is part of a very large sketch (1,381 lines) so difficult to produce a minimum reproducible case, its probably not worth spending much time getting to the bottom of this unless others have similar problems.

The openNext example on its own returns all the 13 file names in my root directory, however when I place the identical code within a webduino web page it only returns 8, I deleted a few files down to 6 and again openNext on its own works fine, but this time in webduino it only returns 3, it seems the same files are missing in both cases.
Any idea why this is happening?
Is there another way of getting the file names from a directory with SDFat to workaround this?
Thanks in anticipation