Ampersand in Filenames - Okay OR Not?

Are we allowed to use ampersands in filenames? Does Opus have a problem with them or just me? Like I get the feeling sometimes Opus doesn't like me using them, but other times it's okay.

I have a folder with 180 photographs.

I did a batch rename on all these photos from:
YYYY - S+R Wedding, Hawaii - 001, to:
YYYY-MM - S & R Wedding, Hawaii - 001

By the time it finished the 10th or so file, Opus froze up, and also my whole PC. Couldn't move the mouse, nor even ctrl-alt-delete to bring up Task Manager. Rebooted to fix it.

Went in that folder again, tried to batch rename again, and before any files were named, same issue. So I've stayed clear of that folder for a while.

I've just gone into it again, and looked at the files for 20ish seconds in details mode, (10 files still named with the & and the rest with the +). Moused over one, and displayed a thumbnail of the pic, and then computer froze up again. So this time, just by having the folder open in Opus without doing anything caused the PC to just freeze.

Rebooted, went into explorer, and removed the ampersands from those 10 files. Went back to Opus, and now no issues with opening that folder for any time.

Opus doesn't care whether or not the files have ampersands.

A user-mode application like Opus cannot (without really trying, anyway) lock the machine up so much that the mouse pointer won't even move.

Opus may be doing something which other programs don't do and which triggers the problem, but the actual cause of problem is likely to be in something more low-level. For example, an anti-virus scanner, the HDD (physical errors on the sectors used for those files, for example, or just a corrupt filesystem), video drivers (if it was something to do with display a tooltip or generating a thumbnail), etc.

Since you can get the lock-up to happen when just showing the thumbnail for one of the files, I'd suggest working through the FAQ on crashes when viewing certain directories. That has steps on working out which component may be responsible.

Okay cool thanks. Guess it's just been a coincidence that things happen when I use ampersands.

I've never done a disk check, so I'm gonna start with that. Will look into the rest as well.