0.1RC2 introducing blank lines in messages

[angusm]

I have 0.1 RC2 installed on a Fedora Core 7 server, PHP 5.2.5 on Apache 2.2.8.

'enable_htmleditor' = false
'prefer_html' = true

When I send a message using Roundcube, the resulting message has extra blank lines inserted between each line of the message, as if it were inserting two linefeeds in place of one after every line. It does this on both quoted text, and on new text.

Is this a bug or a feature? And if it's a feature, how do I switch it off?

Thanks

Angus