Can't upload but can dowload - failed access?

Just downloaded today and for some reason I can't upload anything, but I can download. This is what the log says.

[16:52:13] Transfer failed.
[16:52:43] Remote file exist check: "127.TIF".
[16:52:43] SIZE 127.TIF
[16:52:43] 550 Access is denied.
[16:52:43] File exist check failed. File not found or permission denied.
[16:52:43] PASV
[16:52:43] 227 Entering Passive Mode (82,45,250,87,4,115).
[16:52:43] Opening data connection to 82.45.250.87 Port: 1139
[16:52:43] STOR 127.TIF
[16:52:43] 550 Access is denied.
[16:52:43] Transfer failed.
[16:53:13] Remote file exist check: "127.TIF".
[16:53:13] SIZE 127.TIF
[16:53:13] 550 Access is denied.
[16:53:13] File exist check failed. File not found or permission denied.
[16:53:13] PASV
[16:53:13] 227 Entering Passive Mode (82,45,250,87,4,116).
[16:53:13] Opening data connection to 82.45.250.87 Port: 1140
[16:53:13] STOR 127.TIF
[16:53:13] 550 Access is denied.

Any help much appreciated!!

The log says that you don't have permissions to upload. Please contact your web hosting provider for assistance.

Regards,
Mat