sqlQuery truncates XML field in SQL Server

Hi all,
I execute a sqlQuery command which includes a field of type XML (SQL 
Server 8 Express) and the result is truncated to 255 chars. I suppose it 
assumes that the XML field is a NCHAR(255). How can I work around this?

Thanks in advance for any tip.
Regards,
Carlos


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platform       i386-pc-mingw32            
arch           i386                       
os             mingw32                    
system         i386, mingw32              
status                                    
major          2                          
minor          8.0                        
year           2008                       
month          10                         
day            20                         
svn rev        46754                      
language       R                          
version.string R version 2.8.0 (2008-10-20)