That's strange.
Maybe you should try restarting your computer and using another browser such as Firefox or Internet Explorer. Are you such you followed the directions in the preset sync thread correctly? Try reexporting your preset and uploading it again. You could also try restarting your internet. I'm honestly not sure why it would be doing that; maybe someone else has some more infomation. ^^
Arr, this is strange.
I suggest makin' sure yer internet is well connected and has all full bars. It sounds to me that there's an interruption in the transaction that's restrictin' ye' from properly uploadin' yer preset file(s). It'd also be good in givin' the suggestions provided by Ms. Eclipse a try.