>>>>> In <hh64umnjqj.fsf@blah.pl> Maciej Matysiak wrote:

> It has just happened again. Now I set debug-on-error and saved
> the buffer (attached). It seems, that there's problem with the "ó"
> character, it's not encoded in iso-8859-2 like the rest of polish
> characters in that word.

(let ((mm-coding-system-priorities '(iso-8859-2)))
  (nnrss-mime-encode-string "ó"))
 => "=?iso-8859-2?Q?=F3?="

Hmm, there may be another real cause.  I think two or more
charsets were required to encode the text then.  In such a case,
the UTF-8 charset will be helpful.  Aren't you using the
Mule-UCS XEmacs package?

> Debugger entered--Lisp error: (error "Can't rfc2047-encode `...

The text in question seems to have been modified by the debugger
or something.

> Anyways, I'd be really happy if gnus would update the number of
> messages in each grup despite the rss error. Now it's just displays
> "Can't rfc2047-encode ..." error and stops.

This is a last resort, though.