You can upgrade your HX2110 to WM5.0 without accouring any problems. For the 2700 series the upgrade is offically released by HP. So just download that. But there will occour a SK-check so we have to trick out the HP-money-trap.
Step by Step now:
1.) Download WM5.0 upgrade for 2700 series
2.) Download 2003 upgrade for 2000 series
3.) Bring your device in BL-mode by pressing CONTACTS and ITASK (curved arrow) together with PENs softreset
4.) Start with 2003 - accept the EULA und you'll see comparism HW-upgrade device and ROM-file
5.) Now exchange the NBF-Flashfile from 2700 series with that from 2000 series (rename the 2700 file exactly as the 2000)
6.) Start upgrade progrcess
7.) Format PS by pressing CALENDAR button, the POWER button, and the MESSAGE button and PENs softreset.
8.) You'll see PS-Formatting on screen
9.) Wait a while even the progress bar reaches 100% (it took time to init the whole system)
10.) voila .... WM5 in your desired language
If you use original HP-flash-tool then aware of language check, you can't flash a Italien PDA to English by using original toolset (use patched therefore) but with the flash-file-swap-trick you can trick out SK-check

Please report suggestions and problems