I just delete the default launcher...
Deleting the launchers doesn't seem to help when using Widget Locker
Bear with me, I'm a new iOS convert to android.
For me, it seems that denying Widget Locker root access through Superuser solved the problem.
Here is what's working for me on rooted Samsung Galaxy S II, AT&T:
I did delete TWLauncher using Titanium Backup but I don't think its necessary
I deleted all other launchers as well
Went into Superuser and deleted the entry for Widget Locker
Went into Widget Locker and turned off Home Helper and Root Helper
Set LauncherPro as default launcher
Downloaded Default App Manager and set system defaults. This isn't necessary but beats going through all the settings to assign defaults
The only issue I see is that, if you are an avid Widget Locker user, as am I, and using a phone like SGSII, the home button will bypass the unlock swipe/button/action. Small price to pay I think.
So far...so good. I know this is an old thread but there doesn't seem to be much in the way of answers about it anywhere just LauncherPro supporters blaming Qik or whatever. I'll update this if I have anymore trouble but it seems to work.