I have only once uploaded 1 photo to a thread from my phone. No problems... But I too have a hard time sometimes sending more than one.... With my BB torch 9860 it must depend on the size of the file and how many I attach. I think the problem may be my hotmail account I use. It could be my service provider.. but there shouldn't be any limit on data..?
I typically can send 3 pictures at a time to any one. If I want to get a pic off my phone and on to the laptop I send myself a email with the pic attached. This is quick and I know the file is in my email and downloads to the download file. Saves plugging the phone in and getting all the pictures again.
Not trying to brag but I believe I have found a better way....Maybe it could work for you.
I never have to tether my phone to computer. All my computers have Bluetooth along with phone so all I have to do is select one or multiple pictures I want to transfer
(Even From Cockpit or out on the dock) to Nav-computers cloud folder. So if I am at say boat I can send new picture directly to computer at nav-station. Even to laptop from other locations. Which then automatically uploads to cloud. Were the cloud folder will automatically update to office, laptop,boat. I even have remote access to my account from any computer or my I-pod.