Location of instruments in the orchestra...

I'm streaming a recording of Beethoven's Symphony No 1 in C Major.  It seems that the violin section is on the right side of the recording and the cellos and basses are on the left side.  From my experience (I have sat front row at many symphony concerts), the violin section is always on the left side and the cellos on the right (sometimes the basses are on the left, sometimes on the right).  

Do you think this is the fault of the recording or the mixing, or should I reverse my speakers?  How do you know if you have the speakers on the correct sides?  What do you think?

The standard seating is not universal.  
Could be the source has the channels reversed.

Check all of your connections to be sure they are plugged in correctly. If you have a CD or LP of a another symphony play it and see if it is correct. 
There is a somewhat common practice called "split violins", where they're divided left and right, but if they are all clearly on the right, then as newbee say, the channels got reversed somewhere in the chain.  It may be in your system, but if other recordings sound right, it's likely somewhere in the part of the chain that prepared the recording for streaming.
I've found that the apparent layout of instruments on classical recordings often is not what I'd expect. I suppose that at least in some cases, the sections are rearranged for ease of recording.
Some conductors prefer different positions for the various string sections. I have seen first and second violins on opposite sides of the orchestra, and sometimes the celli and violas are switched.  I have also seen situations where the company making the recording made the mistake (in one case on a Classic Records reissue on their 24 bit DADs, the reversal came between the first and second movements of a Gershwin piece). 

All that said, agree with Newbee.
+1 rcprince. Yes, first and second violins sometimes on opposites sides; particularly effective with Beethoven as he often wrote for the first and second violins to trade phrases; however, I don’t think I have ever seen first violins on the right side. Sounds like what you have is an accidental reversal of channels prior to pressing.