Are all of the transitions watermarked?
IIRC without the permanent keycode it should run unrestricted for a while and then the "Pro" features would become watermarked again - but the "BAS" or "STB" ones ought still to show up without watermarks... If all the transitions are watermarked then I'm not certain whether having a permanant keycode would fix it.
The old Pinnacle "Club Hollywood" site that used to give out the keycodes is long since defunct; for certain products such as TD Pro (supplied with Liquid) they can still be registered and a keycode obtained. Otherwise you could try asking tech support to generate you one (but they might not be interested in doing it for such an old product and its intended use!).
Do you have a record of the registration information that you got for HFX Pro the "first time around". If you have that information you can easily get the old permanent keycode to work on the current PC:
You ned to have a matching set of numbers from the old registered/working PC:
i. The product serial number for HFX 5.2 Pro
ii. The Machine ID of that computer (this is actually the Volume Serial Number of the C: drive)
iii. The permanent keycode.
To re-use the old permanent keycode, locate and download the free tool "VolumeID" and use it to set the C: drive's volume serial number to the same hex. digits as in your old Machine ID. So if the Machine ID was 12345678 you would use the command
volumeid c: 1234-5678
Then start up HFX Pro, get the "registration" page displayed and click on the "Enter keycode" link. Put in your old permanent keycode and it should now be accepted.
Changing the hard drive volume serial number will be regarded as a hardware change as far as Windows Product Activation goes (at least for XP) - so if you have used up your allowed "quota" of changes since the last activation you might have to re-activate. It could also interfere with other copy-protected software that makes use of the hard drive volume serial number to prevent unauthorised copying from one PC to another (any such software might need to be re-installed or re-authorised in some way).
HTH
Richard