This problem just came up.. so I'm concerned it's a service pack or windows update issue. Just recently, my XUpload application is not behaving correctly when users access the application with IE and hit port 443.
My app uses inline progress bar. The file no matter what get's uploaded to the server, but the progress bar stops around 2-5% and "hangs". Then a message in the status window will say "Upload Failed". But actually the upload is still progressing in the background. It almost seems like the upload_status.cgi is unreachable after the first request.
This works perfectly with Firefox. I've tested with multiple servers, and it is reproducable on all.
My IE version:
6.0.2900.2180.xpsp_sp2_gdr.050301-1519
Updated Version:; SP2;
Here is the screen shot of the progress + error

Again, like to state that this works fine in Firefox (also tested with Opera on Windows). This use to work until recently. This is reproducable on multiple (three servers) when uploading with SSL. I can also confirm that this happens with multiple users (2 using IE6 and 1 using IE7). No code changes have been made.
My version of XUpload:
XUploadPro-2.3
Any help is greatly appreciated!
Thanks!
hanji