can't publish to bi-ce 5.1 from PRD 5.01

Hi

Downloaded the brand new bi-ce server. Same machine where I got a bi-ce 5.0 working flawlessly. Stopped 5.0 and started 5.1
Opened a working report in PRD 5.01 > publish > set url and credentials:

"unable to publish your file. Please try again or contact your system administrator"

Taking into account that environment is the same as 5.0, and the only change is bi-ce version, I guess if there's a bug regarding publishing a report from desktop machine.

thanks in advance