DougCuk

I had this problem too - and after some discussion on another thread we discovered the cause. The server was set to offer GZipped versions of ALL files - which can dramtically reduce server download bandwidth The receiving browser is supposed to transparently un-GZip the file and return it to its original format However when using older versions of Internet Explorer a downloaded ZIPfile remains GZipped - which baffles most UNZIP utilities. Downloading using Chrome or Firefox should work OK - the file is saved as a plain ZIP file as expected. Apparently this was a known issue with IE6, IE7 and IE8 - but was never fixed. Supposed to be fixed in IE9 and newer Documented by MS as a fast published "emerging issues" article (2009/2010) - but no fix was ever implemented. http://support.microsoft.com/kb/2002350 The two offered resolutions are basically: Option 1 - Disable HTTP (GZIP) compression for .ZIP files on the web server. Option 2 - Change the MIME type for .ZIP files on the web server from application/x-zip-compressed to application/octet-stream. Also discussed here: http://serverfault.com/questions/77740/corrupt-zip-file-when-downloaded-from-apache-with-internet-explorer GZipping compressed files - such as ZIP files - is generally a waste of CPU time, for no significant reduction of filesize.

I was downloading your zip file using IE8 - not the most secure browser I will agree - but that is a whole other topic! Apparently this was a known issue with IE6, IE7 and IE8 - but was never fixed Documented by MS as a fast published "emerging issues" article (2009/2010) - but no fix was ever implemented. http://support.microsoft.com/kb/2002350 The two offered resolutions are basically: Option 1 - Disable HTTP (GZIP) compression for .ZIP files on the web server. Option 2 - Change the MIME type for .ZIP files on the web server from application/x-zip-compressed to application/octet-stream. Also discussed here: http://serverfault.com/questions/77740/corrupt-zip-file-when-downloaded-from-apache-with-internet-explorer

Looks like another IE8 incompatability to add to the list. It seems that IE8 gets the raw GZipped version of the file from the server - and does no conversion back to straight ZIP format The file you get with IE8 still has a GZip wrapper around the ZIP file. WinRar will remove this wrapper - if it understands what it is dealing with

Was using IE8 on XP Just checked using Chrome and file downloads OK - with the file size you quoted Did a file compare and there is an 11 byte header added to the file plus there are periodic blocks of 5 hex bytes inserted into the file at regular intervals - weird. Have encountered cases where a downloaded file was incomplete - but never with regular internal corruptions.

I am having trouble extracting your file: UDC-01.14.14.zip I have download several times - the file size is always 714 KB (731,607 bytes) - which seems correct - but file doesn't seem to be a standard format ZIP file. WinZip says - Cannot open file: it does not appear to be a valid archive. Win7's Inbuilt Extract says - Please insert last disk of Multi-Volume set and click OK to continue WinRar says - The archive is either in unknown format or damaged If I remove the zip extension - WinRar then reports the file is a GZIP Unix archive file Renaming the file as a GZ file seems to solve the problem - both WinZip and WinRar now extract the file OK Maybe this file needs a redo to sort out this issue?