Trouble uploading phone pics imported to PC

[emu26]

As the title suggests I am having trouble uploading photo's that I have taken on my phone, an HTC Aria. I have imported the pics onto my PC first, resized them using paint.net to the proper sizes, saving them as jpegs but every time I try to upload them the upload fails.
I have had no problems uploading countless pics from my PC that have been taken with traditional digital cameras.

Any suggestions?

TIA
Stuart