ImageList/Memory errors suddenly occur in app

Hello all. I know it is difficult to diagnose a problem "blind", but what I am looking for at this point is a general direction to persue, based on the following symptom description.

The user has been running the app in question for over a year with no issues like this (this is a VB2008 business/database application with an executable 4.6 MB in size). Starting last week, "all of a sudden", the user started getting INTERMITTENT error messages like the following:
Exception has been thrown by the target of an invocation.
Creation of the ImageList handle did not succeed.
Out of memory.
Parameter is not valid.

The last two have been accompanied by the big "red cross" on the form (in the screen shots the user sent me).

The fact that the one message mentions "ImageList" and poking around on the Internet for answer on "Parameter not valid" points in the direction of a graphic problem, but nothing has changed in this area for a long time, and the app only uses graphics in a very straightforward way, using images on buttons and menu items, but not doing any in-line graphics methods.

Any ideas?

the big red cross is the form/picturebox/whatever errorImage + it appears when there is a problem drawing the image to the object