Since the new release, MyC4.com has encoutered repeated accounting problems, sometimes with wrong interest calculations, sometimes requiring correction of user account balances. 

Examples of incidents: 1, 2, 3, 4, 5

MyC4's staff has been quick to respond to the problems and usually is fixing them fast.
But I believe the issue here is, that p2p lending through a foreign internet startup requires a great amount of trust. And while lenders are used to bugs in new internet application, they do expect a high standard when it comes to accounting. After all no user of online banking would accept that he has to check the interest calculations made by the bank. 

The MyC4 team did a good job developing the platform so far and earned at lot of trust; but if the problems persists this might be an obstacle to further growth.