Try running Firefox in Diagnose Firefox issues using Troubleshoot Mode. If it works correctly in that configuration, then one of your add-ons is the culprit.

same problem in safemode. obvioursly it's bug of firefox 4.

pls see the attached screenshot.

Click Windows Start button, go to Settings and then Control Panel. Find Java in the list and then click the "Update Now" button.

Reboot and then try hotmail again. I have the same setup as you, but don't have a problem sending attachments by email.

thank you for your reply. The java in my pc is already the latest version.

That's odd. It shows in your system specs as 1.7.0, but when I try to update 1.6.0_24 which I have installed, it tells me I have the latest version. Where did you download that one from?

Maybe try disabling IE Tab 2 which will disable the Microsoft ActiveX control in Firefox to see if that makes any difference.

Dear Xircal, thank you so much. I have uninstall all the add-ons one by one. Finally, I found the problem is caused by the fantastic add-on "Pentadactyl" (nightly version). After uninstall it then re-install the stable version. All functions in hotmail is OK now. Thank you for your great help. Thx.

You're welcome.

Can you click the "Solved" button? This will take your post out of the loop.

Thanks.

You don't have to disable any addons or extentions!!!You guys are not going to believe this I figured out the problem it's really dumb...ok here goes the attachment uploader loads seperate so I got to thinking it's a popup so I went to options content and under block pop ups there is an option exceptions click on that and in the box type firefox.com and hit allow pow its fixed!!!!! :-)