Just in case anybody else has this prob. I got a resolution by going to the HP Forums and posting a question in their IPAQ thread. The answer was:
Uninstall the keyboard, install BT keyboard driver update from
http://h18007.www1.hp.com/support/files/HandheldiPAQ/us/download/22441.htmland then install keyboard again.
Keyboard works fine, however my old problem of multiplying ampersands has recurred. When using the keyboard, you can use shortcuts to access menu options. When you show the menu option, these shortcuts appear as ampersands i.e.
&Beam Document...
S&end via E-mail...
Each time I open the menu item, an extra ampersand gets added, even if I'm not using the keyboard.
It ends up looking really wierd,

&&&&&Beam Document.... and S&&&&&end via E-mail...
Not a really critical problem. At least the keyboard is working now, but I would have expected that to have gone away after installing the new driver.
Does anyone else have this problem, or is it just me?