Weird error message.

[Warwick via Digitalmars-d-learn]

Dont know what to make of this, I pretty much get it every other 
time I call rdmd. It'll alternate between running fine and then 
giving me this error...

C:\Program Files (x86)\Notepad++>rdmd J:\Code\statproc.d
std.process.ProcessException at std\process.d(550): Failed to spawn 
new process (The process cannot access the file because
  it is being used by another process.)
----------------
0x00434C59
0x00426F47
0x00403C9C
0x00403D17
0x0042F60B
0x0042F521
0x0042258C
0x76B533CA in BaseThreadInitThunk
0x775A9ED2 in RtlInitializeExceptionChain
0x775A9EA5 in RtlInitializeExceptionChain

Any ideas?