Try clearing the data, then if that does not work uninstall & reinstall.

I use it and it worked just fine, even after updating to 2.2

 

Menu-->Settings-->Applications-->Manage applications-->Lockpicker-->Clear data

 

even though it says it will not work with 2.2, i just dl'd it and installed and it worked fine for me.

 

I had always used lockpicker to disable the lockscreen password enforced by my Exchange mail security policy. Thus, no lock pattern used either.

Updated to froyo. Things still seemed to be working fine.

I then decided (foolishly) to try and just enable a pattern lock. I uninstalled lockpicker, removed my exchange account and set it up again (I think this was my mistake). It now asked for a PIN. I then re-installed lockpicker and enabled it, but now can't remove the PIN requirement and lockpicker doesn't seem to work for Froyo now as the dev says.

Is your lockpicker working after a reinstall on Froyo?

 

Thanks for the tip, however doesn't work. Cleared data on Lockpicker - removed it and re-downloaded + install.
First seems to work when putting the Desire to sleep and back agian. However after lock period it still asks for the code

 

I have the same issue. HTC Desire. 2.2 UK Vodafone stock.

It was working fine with Lockpicker, even after upgrade to 2.2.

then I did a Factory Reset for another issue, and when I installed everything again, suddenly I needed the PIN. Can't work out how to get back to the old set-up.
Any ideas?

Does the order that you set everything up after a factory reset make a difference?