Underscores not always printing

[talleyrand]

I suspect this a printer-specific issue but our office printer died and they replaced it with a not-so-gently-used Dell 5100cn I thought I went mad in a meeting as all my code was suddenly devoid of underscores. I have now come to realize, it's hit or miss whether it prints underscores. For example, clnt_acct_id exists in the exact same row and column in two different files. File A, it prints "clnt acct id", file B "clnt acct_id"

Search says I'm searching too fast but I couldn't find a similar issue with the query I got in.

I suspect it's a driver issue as I changed my print font from the default Courier 9 to Courier New 10 and reprinted the same document and it seemed to work fine.

Thoughts?