Why does phobos have collisions?

[Mike B Johnson via Digitalmars-d]

Error: template std.algorithm.mutation.strip cannot deduce 
function from argument types !()(string), candidates are:
src\phobos\std\algorithm\mutation.d(2280):        
std.algorithm.mutation.strip(Range, E)(Range range, E element) if 
(isBidirectionalRange!Range && is(typeof(range.front == element) 
: bool))
\src\phobos\std\algorithm\mutation.d(2287):        
std.algorithm.mutation.strip(alias pred, Range)(Range range) if 
(isBidirectionalRange!Range && is(typeof(pred(range.back)) : 
bool))

This is on a line of code that simply strips away a string...

and works fine when using standard strip(without importing 
std.algorithm)... but when importing std.algorithm too, those 
errors pop up... seems like a defect.