ActionMailer Caching

Hi everyone

I've a big problem with sending a mail over ActionMailer::Base (HTML mail). I deploy my app with capistrano (2.5.9) and use passenger (2.2.15) / apache as webserver. But sometimes, when a send a mail, it takes an old template (of an old release of capistrano) and encode the content not to html. The template has the extension ...text.html.haml. The email receive every customer as followed:

<html> <head></head> <body> <p>Dear Customer</p> ... </body> </html>

It's very strange, because the symptom occurs not every time of sending. Is it possible, that a compontent in the mail sending-chain is caching an old template and doesn't encode it?

I've no plan whats wrong! Please help me... Thanks!