Question: Maple18 generates inconsistent outputs for the same expressions and commands

I encountered the problem with .m files originally. But MaplePrimes doesn't allow uploading .m files, so I had to save the expressions into the file "EQN_SOL_test1.mla", which is included in this question. Below we load the expressions from the .mla file first, and then save them into a .m file in order to recreate the problem that I encountered.

Now we demonstrate the inconsistency problem with .m files. Notice that Maple generates 3 possible outputs:

The last 2 outputs cannot be reduced to 0 since  is nonzero as shown below.

It seems that with .mla files the problem occurs in a different way! With "EQN_SOL_test1.mla", the outputs for all 50 iterations stay the same as

               (A)

but they may all change to the following different result after retarting many times:

               (B)

In particular, after a large number of test runs (i.e., open the file "test.mw", execute the worksheet, close the file, and repeat), the result (B) has only occured twice. The second appearance is saved here for you to view. Once you re-execute this worksheet, most likely all outputs below will change back to (A), and (B) will only reappear after a large number of reruns.