Upload problem

Hello,
i am havin a problem with uploading. I tried many times but i could not attach a file with size more than 40kB in gmail and other accounts also.
i am havin the same problem while uploading photos to orkut. Is there any problem with the modem. I am using the modem "bsnl UT300R2U".
I am havin this problem since i hav got a broadband connection that is 20 days..
I hav tried uploading in different browsers- internet explorer, google chrome, safari, mozilla firefox...etc

please help....