Hi, I am trying to map affymetrix IDs to gene ontology terms using mouse4302.db R library. I noticed some discrepancies in the results, which depends on the way the mapping is performed. An example below for GO:2001030

require(mouse4302.db)

### using as.list()
x = as.list(mouse4302GO2PROBE)
x["GO:2001030"] # output is NA

### using select()
s = select(mouse4302.db, keys(mouse4302.db), 'GO')
s[grep("GO:2001030", s$GO),] # output gives 3 affy IDs

I would expect that the as.list() and select() methods would produce the same results - am I missing something?

Any suggestions would be much appreciated!