template path in cfmodule

Why doesnt this code work?

<cfmodule template="C:/ColdFusion8/cache/custom.cfm" result="myNewVar">
This should come in green again...
</cfmodule>

I get the error as:
The filename, directory name, or volume label syntax is incorrect

whereas this works perfectly fine:

<cfmodule template="..\..\cache\custom.cfm" result="myNewVar">
This should come in green...
</cfmodule>