need a little bit more info please…

sounds like a js conflict, so a link would be helpful to check for obvious conflicts…

are you using the combined js cache?  forum – options – global settings…  

any wp caching plugins?  or js minimizers?

Thanks for getting back to me. Yes we do have a js minifier and possibly something else. I’ll try disabling these and see what happens. 

Thanks.

I’ve just disabled any minification and the problem still occurs.  Also I can’t find an option for “combined js cache” on the global settings page.

We’re using SimplePress 5.1.4 if that makes a difference.

still could use a link to site…

what version of uploader?  since your sp version is pretty old and dated, if you updated the uploader, you may be running incompatible versions…