R help - Dec 2006 - Help to understand an Error using summary to an mcmc object

Hi, 

I used the MCMCirtKd function of MCMCpack: 

posterior2 <- MCMCirtKd(data, dimensions = 2, 
+                    burnin = 5000, mcmc = 50000, thin = 10, 
+ verbose = 10000, B0 = .25, store.item = TRUE, item.constraints = 
beta.constraints) 

And after apply the comand summary() I got some erros and warnings that I 
could not understand: 

summary.posterior2 <- summary(posterior2) 

Error: NA/NaN/Inf in foreign function call (arg 1) 
In addition: Warning messages: 
1: algorithm did not converge in: glm.fit(x = X, y = Y, weights = weights, 
start = start, etastart = etastart, 
2: step size truncated due to divergence 
Error: NA/NaN/Inf in foreign function call (arg 1) 
In addition: There were 42 warnings (use warnings() to see them) 
Error: NA/NaN/Inf in foreign function call (arg 1) 
In addition: There were 35 warnings (use warnings() to see them) 
Error in glm.fit(x = X, y = Y, weights = weights, start = start, etastart = 
etastart,  : 
        inner loop 1; cannot correct step size 
In addition: There were 49 warnings (use warnings() to see them) 
Error: NA/NaN/Inf in foreign function call (arg 1) 
In addition: Warning messages: 
1: algorithm did not converge in: glm.fit(x = X, y = Y, weights = weights, 
start = start, etastart = etastart, 
2: algorithm did not converge in: glm.fit(x = X, y = Y, weights = weights, 
start = start, etastart = etastart, 
3: algorithm did not converge in: glm.fit(x = X, y = Y, weights = weights, 
start = start, etastart = etastart, 
4: algorithm did not converge in: glm.fit(x = X, y = Y, weights = weights, 
start = start, etastart = etastart, 
5: algorithm did not converge in: glm.fit(x = X, y = Y, weights = weights, 
start = start, etastart = etastart, 
6: algorithm did not converge in: glm.fit(x = X, y = Y, weights = weights, 
start = start, etastart = etastart, 
7: algorithm did not converge in: glm.fit(x = X, y = Y, weights = weights, 
start = start, etastart = etastart, 
8: step size truncated due to divergence 
Error: NA/NaN/Inf in foreign function call (arg 1) 
In addition: There were 29 warnings (use warnings() to see them) 

Thanks for any comment. 
Gilberto Matos.