Powershell 2 ISE, not stopping on breakpoints in imported modules

Question

When we set breakpoints within a Module we've imported the debugger ignores the breakpoint. Has anybody else seen this behaviour?
This is driving me nuts, we use PowerShell Modules extensively.
The thing that's really weird is I can see the breakpoint if I run get-psbreakpoint

PS H:\Projects\Powershell> get-psbreakpoint | format-list -force


Id       : 0
Script   : H:\projects\Powershell\Shared\SFTP\SFTP.psm1
Line     : 25
Column   : 0
Enabled  : True
HitCount : 0
Action   : 

Id       : 1
Script   : H:\projects\Powershell\Trading\CPPIB\scripts\CppibBorrowReturns.ps1
Line     : 12
Column   : 0
Enabled  : True
HitCount : 1
Action   : 

EDIT: Seems to work if I delete the psd1 (Manifest file)