I was having the same problem and sent an e-mail to Beiks Technical Support. Here is the response that I received which I have not tried yet.
currently, we have a solution for registered users only, which is as follows:
1) set the clock on your BlackBerry to any date before 1/1/2008; you do that via the settings icon from the main menu, then date/time screen.
2) run LexSpell - the one you already have - and it will work this time; enter any wrong word, like ddddd and check it
3) on the next screen, enter your registration key; you can find your key at BEIKS registered users section - get product downloads, activation codes etc.
4) once the registration is confirmed successful, restore the date back to normal
From then on you should not be having a problem, at least until we replace the distributives online to NOT expire on 1/1/2008 for unregistered users.