"Invalid call" ERROR in DirectX, unknown reason for error!

I have a program that uses DirectX 8 and worked fine. I've changed "something" and saved it and can't remember what I changed but now it gives me an error if I try and call anything like "DrawIndexedPrimitive" or "DrawPrimitive". After putting the error number in the directX Error lookup I got this:

VB Code:

'HRESULT: 0x8876086c (2289436780)
'Name: D3DERR_INVALIDCALL
'Description: Invalid call
'Severity code: Failed
'Facility Code: Unknown (2166)
'Error Code: 0x086c (2156)

Does anyone know why it would give me that error simply from tying to draw. btw it does let me draw meshes still using "Mesh.DrawSubset i"
Thanx for any help.

Changed a variable maybe? Locked a surface which should be locked? (oh wait.. that's ddraw ;))

Your best bet is on checking each variable that you are using with the function and check if it is what it supposed to be..

my 1 and half euro cents ;)

Oh well I guess i'm going to have to go thro the whole of my program, I was just hoping someone might have done something similar and known why it happens.
Thanx anyway tho.

I've just checked some of my other DirectX Programs and they all cause this error when they come to a line that uses "DrawIndexedPrimitive" or "DrawPrimitive". Does anyone know any websites that I could check to see if I can find out why this is happeneing?