IMEI blocked and "slice to unlock" won't work

I temporarily lost my iphone 3.0 on Friday night. I called my service provider in Australia and had the IMEI blocked. The phone was then located and returned to me. It now won't "slide to unlock". I am wondering whether it was damaged while it was lost, or whether this is related to the fact that the IMEI is still blocked? I am expecting it to be unblocked in about 24 hours. Any input would be appreciated.