SquirrelMail - incorrect sorting in Sent Folder.

[#1]

In the 'Sent' folder, the 'From' column is quite sensibly replaced by the 'To' column. However, when you click the button to sort by 'To' the sort is still performed on the 'From' data.
This bug is around on a couple of other SquirrelMail systems I use, both of those hosted on Debian servers, and on Squirrelmail versions 1.4.15, 1.4.19 & 1.4.20 RC2. I think I remember it being around on version 1.4.9a as well.
However I can find very few bug reports about it on the web, the most recent is June 2006, which leads me to think this doesn't affect most users. But it does affect Plusnet. Does anyone have any thoughts about this?

[#2]

OK, it is a bug in Squirrelmail & I've found and fixed it (for the other servers I use).
I've submitted a full bug report to SourceForge:
http://sourceforge.net/tracker/?func=detail&aid=2907412&group_id=311&atid=100311
and you will be able to download my modified files from there I think.
However, this bug is only apparent when config $allow_server_sort = false; is set and most documentation says you should set this to 'true' for much improved performance, provided your IMAP server supports 'SORT'.

[#3]

So PN are not using the IMAP sort - I wonder if that is why the Webmail is so slow compared with using IMAP via Thunderbird?