Problems setting parameters

[Mark Powell]

I've updated the latest from SVN, built the project and have been
playing the example provided. In the example, the method called has no
place to set parameters. The WebService API I'm using requires
parameters to obtain the data (of course). I've tried modifying the
example code directly to slap in the parameters, just to see it
working, but get an error when I do so. What format are the parameters
supposed to take? I assume the are NSString objects. Here is the code
and the resulting error (strings replaced with generic strings for the
example):

NSMutableArray *params = [NSMutableArray
arrayWithObject:@"key=value"];
[_oauthAPI performMethod:@"method" atURL:_oauthAPI.baseURL
withParameters:params withTarget:self
andAction:@selector
(performedMethodLoadForURL:withResponseBody:)];
This produces the error:

2009-10-25 10:47:19.651 MPOAuthConnection[18879:a0f] -
[MPURLRequestParameter length]: unrecognized selector sent to instance
0x1724a0

After the performMethod call, it goes deep into the bowels of the
MPOAuthConnection library. So, it could be an error, but if simple
parameter setting is failing, I would assume the error is on my end
and I am providing parameters incorrectly.

Thank you for any help.