Sabatoge or Coincidence?

Sigmabella

At work I am in charge of updating and keeping eductional materials for 2 routine classes that others present & teach. Usually 8 to 10 classes a month.

On Monday  I updated a power point presentation at work and double checked all the information contained in this power point. 

Last night,  I stayed late at work to print the power point and make presentation folders for the class scheduled for today. (today was my day off)

A couple of min ago work calls and wanted to know why the power point presentation for today's class was wrong.I was basically told I will probably get in trouble for this when I work next!

Both presentations were identical...(they are not supposed to be) I know when I left work last night that today's power point was correct since I printed from the thumb drive last night. I never opened the second one so I am positive I did not overrride or save it incorrectly.

I asked  the person from work who called me to check and see what the remaining paper copies looked like. The paper copies that remained were correct.

I am explain to work that as of 8:30 last night the electronic copy of this presentation was correct & that the paper and electronic copy matched.

I know this since I printed the paper copies right before I left for the night!

Now I am concerned that someone is out to sabatoge me!

A few weeks ago the reverse happened. Some of the paper copies were not correct...I know at that time I double checked all these materials as well.

This is the 1st time in 3 years anything has ever been askew for these classes

The thumb drives and materials for these classes are kept where everyone who presents the class has access to them.

At work I always admit when I make a mistake...These past 2 times I know that everything was 100% correct before these classes.

 Am I being paranoid or does it sound like I have a vaild concern?