I don't know but those speeds are around half of normal 3G speeds.
EDIT: Try taking out the sim and re inserting it, resetting all networks settings, than reset the phone. You might have to set up as a new phone like my friend did who recently got a 3GS.
You've missed the whole big issue with AT&T over the last week or so with poor upload speeds in markets where Alcatel-Lucent (ALU) supplies the gear due to a software issue on the network side?