imap_open with variable fails

Hi, I'm using imap_open and the script works fine on my server with 4.3.11. Now as user with 4.3.10 reported that the script does not work. He finally got it working by replacing my variable-names in the imap_open-command with strings containing exactly the same data (except for the leading slash before the { which I was using together with variables). The statement is @imap_open("\{$host}INBOX",$user,$pwd,OP_HALFOPEN); and host is "80.243.163.14/pop3". I know that /notls can also be appended, but as I said: it works fine when entering these directly into the command, just when using the string-parameter it fails. The error is: "imap_open(): Couldn't open stream" I've spent quite some time now googling around, searching various forums etc., but could not find a solution to this. Would appreciate your help very much! Thanks Michael