Today i learned that after 4 month in Cambodia they denied my application for a single entry tourist visa, because i have spend to many times in Thailand

This is unusual as Phnom Penh has always been a place to get a single entry visa without any hassle although the embassy might make you waut but there are ways around that with agents.

Were there any other foreigners there who had the same problem ?

Did you go direct to the embassy or use an agent ?

There's an agent called 'Mr Keo' who has a little shophouse next to the big irish bar on the riverside, it might be worth speaking to him to see if anything can be done about this. The last time I was there he offered a next day service which suggests he bypasses the normal procedure somehow, you might have a little more luck going through the agency route if you haven't already tried this.

I believe this is his address - he will have the best current advice for you as he knows people in the embassy (not sure if the phone number is current) :

LMN Travel Tours
Mr Keo
012 76 74 01
221, Sisowath Quay
(Near Paragon Hotel)

Have you gotten tourist visas from them before? If yes perhaps you reached their limit.

I used an agent in Sihanoukville, i never had a visa for thailand in Cambodia, the agent was told that in my passport over the last 4 years i had to many time in Thailand thats what they say, maybe a new passport will help????

I used an agent in Sihanoukville, i never had a visa for thailand in Cambodia, the agent was told that in my passport over the last 4 years i had to many time in Thailand thats what they say, maybe a new passport will help????

Yes it would, but more simply you can travel to Savannakhet Laos, and obtain a double entry tourist visa on the same day.

Will Savennaketh issue a double entry visa when i out of thailand for 6 months, but have a lot of visa's in my passport?

The do not count past entries or visas at Savannakhet only visas you have gotten from them back to back.