I found some issues with PHP-ExcelReader on a Power PC server with an Excel file containing cells with date format. The conversion would block indefinitely with 100% CPU usage at this line:
$string = date ($this->curformat, $utcValue);
in function "createDate($numValue)" of reader.php. The problem was that the value of $numValue was ridiculously high and it was probably overflowing the date function, putting it in an infinite loop. The problem came from this conversion:
$tmp = unpack("ddouble", substr($this->data, $spos + 6, 8));
The value is stored in little-endian format in the Excel file but it was read as a big-endian binary format on PowerPC.
I added to reader.php a small test to detect the endianness of the host hardware and I reverse the value returned by "substr($this->data, $spos + 6, 8)", using "strrev()" if PHP-ExcelReader is executed on a big-endian host. I included a patch to solve the problem on "reader.php".