[[maeyanes]]

Hice una pequeña búsqueda en Google sobre el problema y encontré esto:

Empezado por W3C Recommendation

C.12. Using Ampersands in Attribute Values (and Elsewhere)
In both SGML and XML, the ampersand character ("&") declares the beginning of an entity reference (e.g., ® for the registered trademark symbol "®"). Unfortunately, many HTML user agents have silently ignored incorrect usage of the ampersand character in HTML documents - treating ampersands that do not look like entity references as literal ampersands. XML-based user agents will not tolerate this incorrect usage, and any document that uses an ampersand incorrectly will not be "valid", and consequently will not conform to this specification. In order to ensure that documents are compatible with historical HTML user agents and XML-based user agents, ampersands used in a document that are to be treated as literal characters must be expressed themselves as an entity reference (e.g. "&"). For example, when the href attribute of the a element refers to a CGI script that takes parameters, it must be expressed as http://my.site.dom/cgi-bin/myscript....&name=user rather than as http://my.site.dom/cgi-bin/myscript....uest&name=user.

Esto es, la url debes escribirla de la siguiente forma:

Código PHP:

<a href="http://burdjia.com/foros/profile.php?mode=viewprofile&amp;u=4">Ñuño Martínez</a><br /> 


Y me imagino que sería el mismo caso de Dec