Recovering a signal that was upsampled by non-integer factor
The Sampling operation (both upsample and downsample) depends on two very critical conditions: 

1- The existance and applicability of ideal frequency selective filters

2- The operated signal being strictly bandlimited 

For most practical systems these two critical conditions are only approximately met. Hence the computational results by those practical systems are only approximate and not exact.

Note that in case of simple but crude interpolation (upsampling) by zero-order hold, which requires no filter at all as being just a sample replication, you can exactly recover the original samples due to the simplicity of the operation. 

Unless some advanced algorithms are utilized, therefore, some deviation (but controllable) is expected at the output of any practical sample rate conversion systems.