Better be safe than sorry. I had been disallowed reentry the morning of my last attempted cambo visa run as I'd apparently exceeded land visa run allotments and immigration(cambo border) informed me that at this point, only air return would be acceptable. I took a bus to Siam Reep, booked a flight to Subvanapum, was asked for proof of funds & onward travel. Was only able to produce 200 as I'd exceeded my daily limit paying for multiple bus rides and plane ticket so detained for 6hrs & deported back to Siam Reep. After an ordeal bus ride to Pnom pen, an unwanted weekend stay, counterfeit change FROM the window at the Thai embassy and an ATM, I was permitted reentry 9 days later with a 30 day. The embassy did require an atm receipt and copies of onward travel. No problem this time, but had funds in pocket and my flight ticket just in case. I'm sure I created the highpoint of the deportation officers career. Maybe I just had really bad luck but BE PREPARED