Mashie over at Howardforums published this tip:
“It looks like someone over at Treo Central figured out how to enable HSPDA on the 750. I don’t live in an area that has HSPDA yet so I have no way to test it. Here are the instructions and thanks to bigben for posting over there…
I like a number of you have tried to get the HSDPA working on the Treo 750v. I believe I have stumbled into the solution.
First, go to a German site called fit4communication anytime at http://www.fit4cat.de/thread.php?threadid=91. Down load a program called “fit4cat Hermes Tweaker” (Windows loader version is what I used). Unzip the file and install it to your Treo 750v.
Second, go to XDA Developers at http://wiki.xda-developers.com/index…e=Hermes_Utils and download SetHSDPAv2.zip. Unzip the file and copy to the mobile device windows directory.
Third, on your Treo 750v start the “fit4cat” program. Scroll done and click the phone tab, select “enable” for HSDPA. Click “File” option on the bottom of the screen, selecting the save before exit option.
The Treo 750v will do a soft reboot.”
Editor Note: Warning, do this and any registry hack at your own risk.