I use the attribute description extensively. I often click on an attribute to open that attribute properties window. All I am going there for is to read the description while working on some other document. When that window opens, the field that has focus is the data type. If I look away and move my mouse to my document but scroll or similar before I click – it changes the data type in the attribute properties window. Many times every week I end up changing data types by mistake. Usually I cancel out of that window, but sometimes simply click OK when I am done. When I next run an alter script and apply to my database, I change the data type in that database. Again, this will sometimes result in some sort of error message, but sometimes not. For instance – I recently, by mistake, changed a field from integer to decimal. The database accepted that without complaint, but this caused a problem when trying to reverse that mistake.
Please consider giving some other field focus when that window opens (or even better – make the user click on something to give it focus). If you choose another field, I would suggest the description, because if that changes by mistake, it will not mess up the database. Alternatively, make that field ignore the scroll feature until the dropdown is chosen. (Do something to make it less easy to alter the field)
Long ago, this was not a problem, so I am guessing that this field getting focus is something that was introduced not that long ago.