ok, thanks for the heads up.
i havent been able to reproduce the bug you speak of but will keep an eye out for it.
incase anyone else needs this solution, the best way to make it work is the following....
follow martins instructions for all the code, but set the namespace in the class to something of your choice - i used 'Fixes'.
because the root namespace for my web project is already GHC this means that these classes live in the namespace GHC.Fixes
so in your web.config where you add the tagprefix put the full namespace for the class also... Note that my tags will be prefixed with 'Fixes' rather than 'martinbeeby'
<add tagPrefix="Fixes" namespace="GHC.Fixes"/>
Then in each page that you use these new controls you must add a register directive at the top of the page like so...
<%@ Register TagPrefix="Fixes" NameSpace="GHC.Fixes" Assembly="GHC" %>
The Assembly attribute is the name of the dll (minus the extension)
that contains the controls. My dll compiles down to GHC.dll so my
assembly attribute has a value of GHC.