After reading the issues regarding opening up the SRT5490.zip file for the new firmware ver 2.2.6-17.7.07 as posted by DimWit I downloaded the file and am happy to report that the file is not 'corrupt' and can be opened by using 7-Zip.
The file inside the SRT5490.zip (8,700kb) is SRT5490_V2.2.6_TOTAL (9,200kb).
7-Zip can be downloaded here http://www.7-zip.org/
