Nissan Repair: Maxima Transmission, transmission issues, valve body

Question
I have a 93 Maxima 3.0L that is having some transmission issues that are confusing me.  3 weeks ago it was running perfectly.  Then it began intermittently getting stuck in 1st gear.  Normally, I drive about 4 miles to work and it is fine.  At lunch I drive 4 miles home and it is still fine.  When I leave to go back to work it usually will not shift out of first gear.  Then, after sitting the rest of the day it works fine on the way home.  
Yesterday it did something different.  While I was driving home for lunch it suddenly went like it was in neutral.  I checked to see that the shifter had not moved, which it hadn't, and then it went back into gear but was stuck in 1st again.
I have noted one thing when it is not shifting.  If I put it in park and back into drive the transmission engages very hard.  Normally I cannot even feel it when I put it in drive.
The fluid and filter are only about 10,000 miles old.  The car has 184k on it.
Any ideas what's going on?

Answer
John,

Sounds like the valve body is sticking and you should change the filter and fluid.  If this does not do the trick you are looking at taking it in to have the transmission examined as the valve body probably have gummed up or has debris in it and it will need to be removed and cleaned out and reassembled.