Bug#549312: Looks as if this only occurs with more than 1 dvd

[ael <law_ence.dev@ntlworld.com>]

This bug is still present on all my machines including on a netbook
with a freshly installed squeeze.

However, I am fairly sure that it only occurs when multiple dvds
need to be mounted (necessarily sequentially, since there is only
a single mount point). It is as if the path to the deb on the earlier
dvds is cached somewhere: the dvd is changed, and when that cached path
is used later, it is, of course, no longer valid.

This bug would seem to make debian installation from multiple DVDs
nearly impossible: so pretty serious for those without high
bandwidth connections.

ael