[Users] Is a DOCTYPE recommended for GeoExt?

[Adam Ratcliffe]

I generally use the HTML 5 doctype when developing web apps and have
so far used this successfully with the ExtJS apps that I've built -
despite Sencha recommending not to use a DOCTYPE:
http://www.sencha.com/forum/showthread.php?74497-What-doctype-should-I-use-with-Ext-JS

I've now come across a layout issue under IE7 that I've only been able
to resolve through removing the page DOCTYPE.  If I leave it out is
this likely to cause any problems for GeoExt or OpenLayers components?

Cheers
Adam