diff --git a/R/misc_and_utility.R b/R/misc_and_utility.R
index b06731203..d190a6c0e 100644
--- a/R/misc_and_utility.R
+++ b/R/misc_and_utility.R
@@ -4519,6 +4519,7 @@ umx_scale <- function(df, varsToScale = NULL, coerce = FALSE, attr = FALSE, verb
 #' umx_is_class(mtcars, c("character", "numeric"))
 #' # Is zygosity a factor (note we don't drop = F to keep as dataframe)
 #' umx_is_class(twinData[,"zygosity", drop=FALSE], classes = "factor")
+#' umx_is_class(mtcars$mpg) # report class of this column (same as class(mpg))
 umx_is_class <- function(df, classes=NULL, all = TRUE){
 	if(!is.data.frame(df)){
 		if(is.null(classes)){
@@ -4532,7 +4533,7 @@ umx_is_class <- function(df, classes=NULL, all = TRUE){
 	i = 1
 	if(is.null(classes)){
 		for (n in colNames) {
-			bIsOK[i] = class(df[, n])[1]
+			bIsOK[i] = class(df[, n, drop = TRUE])[1]
 			i = i + 1
 		}
 		return(bIsOK)
diff --git a/man/umxPower.Rd b/man/umxPower.Rd
index d402b8d64..a6a3a1305 100644
--- a/man/umxPower.Rd
+++ b/man/umxPower.Rd
@@ -98,28 +98,28 @@ pwr::pwr.r.test(r = .3, n = 90)
 umxPower(m1, "X_with_Y", n= 90, method = "empirical", explore = TRUE)
 
 # Search X_with_Y:power relationship for n=90
-|    | X_with_Y   | power     | lower     | upper     |
-|:---|:-----------|:----------|:----------|:----------|
-| 1  | 0.08800859 | 0.2689414 | 0.1596095 | 0.4160855 |
-| 2  | 0.10066598 | 0.3236951 | 0.2117817 | 0.4602180 |
-| 3  | 0.11332337 | 0.3837446 | 0.2747536 | 0.5058168 |
-| 4  | 0.12598077 | 0.4475620 | 0.3469889 | 0.5526166 |
-| 5  | 0.13863816 | 0.5131549 | 0.4249318 | 0.6005657 |
-| 6  | 0.15129555 | 0.5782978 | 0.5032166 | 0.6499256 |
-| 7  | 0.16395294 | 0.6408252 | 0.5758201 | 0.7010404 |
-| 8  | 0.17661033 | 0.6989084 | 0.6383710 | 0.7532292 |
-| 9  | 0.18926773 | 0.7512450 | 0.6901890 | 0.8036907 |
-| 10 | 0.20192512 | 0.7971249 | 0.7332804 | 0.8488375 |
-| 11 | 0.21458251 | 0.8363858 | 0.7698677 | 0.8865116 |
-| 12 | 0.22723990 | 0.8692947 | 0.8014434 | 0.9163789 |
-| 13 | 0.23989729 | 0.8964042 | 0.8289134 | 0.9392231 |
-| 14 | 0.25255468 | 0.9184186 | 0.8528663 | 0.9562632 |
-| 15 | 0.26521208 | 0.9360885 | 0.8737344 | 0.9687514 |
-| 16 | 0.27786947 | 0.9501390 | 0.8918717 | 0.9777896 |
-| 17 | 0.29052686 | 0.9612285 | 0.9075880 | 0.9842729 |
-| 18 | 0.30318425 | 0.9699297 | 0.9211637 | 0.9888940 |
-| 19 | 0.31584164 | 0.9767254 | 0.9328545 | 0.9921728 |
-| 20 | 0.32849904 | 0.9820138 | 0.9428939 | 0.9944916 |
+# |    | X_with_Y | power | lower | upper |
+# |:---|:---------|:------|:------|:------|
+# | 1  | 0.03     | 0.27  | 0.15  | 0.44  |
+# | 2  | 0.03     | 0.32  | 0.20  | 0.48  |
+# | 3  | 0.04     | 0.38  | 0.26  | 0.53  |
+# | 4  | 0.04     | 0.45  | 0.33  | 0.57  |
+# | 5  | 0.04     | 0.51  | 0.41  | 0.61  |
+# | 6  | 0.05     | 0.58  | 0.49  | 0.66  |
+# | 7  | 0.05     | 0.64  | 0.57  | 0.71  |
+# | 8  | 0.06     | 0.70  | 0.64  | 0.75  |
+# | 9  | 0.06     | 0.75  | 0.69  | 0.80  |
+# | 10 | 0.06     | 0.80  | 0.74  | 0.85  |
+# | 11 | 0.07     | 0.84  | 0.77  | 0.88  |
+# | 12 | 0.07     | 0.87  | 0.80  | 0.92  |
+# | 13 | 0.08     | 0.90  | 0.83  | 0.94  |
+# | 14 | 0.08     | 0.92  | 0.85  | 0.96  |
+# | 15 | 0.08     | 0.94  | 0.87  | 0.97  |
+# | 16 | 0.09     | 0.95  | 0.89  | 0.98  |
+# | 17 | 0.09     | 0.96  | 0.91  | 0.98  |
+# | 18 | 0.10     | 0.97  | 0.92  | 0.99  |
+# | 19 | 0.10     | 0.98  | 0.93  | 0.99  |
+# | 20 | 0.10     | 0.98  | 0.94  | 0.99  |
 
 }
 
diff --git a/man/umx_is_class.Rd b/man/umx_is_class.Rd
index b7b943390..1459585c5 100644
--- a/man/umx_is_class.Rd
+++ b/man/umx_is_class.Rd
@@ -34,6 +34,7 @@ umx_is_class(mtcars, "numeric") # TRUE
 umx_is_class(mtcars, c("character", "numeric"))
 # Is zygosity a factor (note we don't drop = F to keep as dataframe)
 umx_is_class(twinData[,"zygosity", drop=FALSE], classes = "factor")
+umx_is_class(mtcars$mpg) # report class of this column (same as class(mpg))
 }
 \references{
 \itemize{
diff --git a/man/umx_set_silent.Rd b/man/umx_set_silent.Rd
index a8b564580..2adf573e0 100644
--- a/man/umx_set_silent.Rd
+++ b/man/umx_set_silent.Rd
@@ -22,10 +22,10 @@ If TRUE, then the progress messages from model runs are suppressed. Useful for p
 }
 \examples{
 library(umx)
-umx_set_silent() # print existing value
-old = umx_set_silent(silent = TRUE) # store existing value
-umx_set_silent(FALSE) # set to FALSE
+old = umx_set_silent() # print & store existing value
+umx_set_silent(FALSE, silent = TRUE) # set to FALSE
 umx_set_silent(old)   # reinstate
+umx_set_silent() # print existing value
 }
 \references{
 \itemize{