It seems that if you are in a module X which imports Foo.Bar, you cannot use :m to get to the Bar module.

X> :m Bar can't find module `Bar' X> :m Foo.Bar strange looking module name: `Foo.Bar'

It appears the remedy to this would be to modify the definition of isAlphaNumEx in ghci/InteractiveUI.hs to:

isAlphaNumEx c = isAlphaNum c || c == '_' || c == '.'

it seems that the code in setContext and newContext know how to handle qualified module name switches; it's just being blocked before they can try.

Thanks, fixed. Simon