Possible bug in R parser

Dear R developers,

A recent typo led me to discover, that R is happy to accept

  > 20x2
  [1] 20

as input. This appears to be related to the parsing of hexadecimal
constants, since there must be a zero before the 'x' (i.e. 2x2 or
02x02 gives the expected error). All this is under R 2.12.1 on both OS
X and Linux. Is this expected behavior?

Cheers,
Olaf Mersmann