lumiMouseV1 trouble

Hello BioC community:

I am having trouble with lumiMouseV1. I am able to go from ID ->
ENTREZID via lumiMouseV1ENTREZID:

> entrezIds <- mget(featureNames(lumi.N), envir =
lumiMouseV1ENTREZID,ifnotfound=NA)
> head(entrezIds)
$iSh39ilew_g4tR.A18
[1] 78928

$`GI_10304988-S`
[1] NA

$oS6QgIgopJKKQ4S9Ko
[1] 16728

$`GI_12963686-S`
[1] NA

$`GI_12963764-I`
[1] NA

$`GI_13385605-S`
[1] NA

However, when I do the same for ID -> GO, every entry is NA.

> haveGO <-mget(featureNames(lumi.N), lumiMouseV1GO,ifnotfound=NA)
> head(haveGO)