When I go to upload a file attachment to a post, I get the non-Flash (standard) uploader. The black "throbber" in the upper right corner displays constantly, yet the browser can sit there for several minutes with no progress.
The same photo attachment will upload through a desktop browser and is only about 60% of the size limit. (File is 2.88MB and my size limit is 5.00MB.)
I have tried this on both 1.1.4 and 1.2 Beta, and it does not work in either one.
Here is how my phone has been sitting for the last 15 minutes or so on my latest attempt: