[BioC] Difference between hgu133a.db and hgu133b.db

[Thomas Hampton]

I  merged  probe ids from affy hgu133a and b chips, then looked them  
up using

mget(probelist, hgu133aSYMBOL)

Then I tried the same lookup with  hgu133bSYMBOL

I expected a difference, since the chips contain fairly unique symbols.

Are symbols unique to A or B known to both?


Thanks.

Tom