Hi,
I have just had same problem with my 2007 peugeot 107- mine started like that and eventually neither indicators would work at all! I took mine to the garage- they checked all wires, fuses and connections, but eventually traced it to a fault with the internal light switch for the indicators. Cost around £45 for part and fitting there once they found problem, and works fine now. I wouldn't even know where to start fixing it myself though i'm sorry! Main cost for me was them trying to find the fault, so maybe if you give them an idea of what it is, might work cheaper for you? I ended up with a £200 bill by the end!
Anna, April 2011