Bletchley remain bottom of South West 1 East after a narrow defeat to fellow strugglers Maidenhead.
Victory at Manor Field would have lifted Bletchley from the foot of the table, replacing them with their opponents.
However, their struggles at this higher level continued to plague them as they slumped to their seventh defeat from seven, going down 33-28.
Olney made it four wins out of five on Saturday as they saw off Oakham 22-13.
Their fine start to the Midlands 2 East South campaign has seen Olney climb to fourth in the standings so far, but face a tough challenge this coming Saturday as they play host league leaders Wellingborough.