Installing packages

Hello,
I have a problem when making packages with version 2.6.1. I have a 
package which I could install in version 2.5.1. I have made some 
modifications of the package, and I would like to install it to 2.6.1. I 
check the package with R CMD check, I build it with R CMD build and when 
I try to install it it gives me an error, it tries to install something 
like R.css and tells me that cannot open the DESCRIPTION file. Then, I 
made the same procedure with version 2.5.1 and it worked fine. I am 
using Windows Vista and I changed the PATH environment variable to 
version 2.6.1. Any suggestion to solve the problem?
Best regards,

Dani

Daniel Valverde Saub?

Grup de Biologia Molecular de Llevats
Facultat de Veterin?ria de la Universitat Aut?noma de Barcelona
Edifici V, Campus UAB
08193 Cerdanyola del Vall?s- SPAIN

Centro de Investigaci?n Biom?dica en Red
en Bioingenier?a, Biomateriales y
Nanomedicina (CIBER-BBN)

Grup d'Aplicacions Biom?diques de la RMN
Facultat de Bioci?ncies
Universitat Aut?noma de Barcelona
Edifici Cs, Campus UAB
08193 Cerdanyola del Vall?s- SPAIN
+34 93 5814126