Common warning messages

[Dazed_75]

Modern drives are not necessary well described by the traditional
cylinder, heads and sectors/track model.  I believe that is the reason
we often see warning messages like those below and so have not been
concerned by them before.  But I just noticed the line about DOS and
Linux interpreting the contents differently.  I believe the extended
partition was created during the ubuntu install as a dual boot over XP
and that Windows has no use for it anyway.  Also, I had an external
drive connected via USB when I did the listing (actually the reason I
did it).  So, several questions:

1) Is there any concern around the DOS and Linux interpreting
differently message?
2) Is there any reasonable means of partitioning to avoid the cylinder
boundary warnings?
3) Is there any concern about sfdisk expecting sda1 to end two
cylinders later than the partition table says?

larry at ldesk:~$ sudo sfdisk -l

Disk /dev/hda: 155061 cylinders, 16 heads, 63 sectors/track
Warning: extended partition does not start at a cylinder boundary.
DOS and Linux will interpret the contents differently.
Warning: The partition table looks like it was made
  for C/H/S=*/255/63 (instead of 155061/16/63).
For this listing I'll assume that geometry.
Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0

   Device Boot Start     End   #cyls    #blocks   Id  System
/dev/hda1   *      0+   3781    3782-  30378883+   7  HPFS/NTFS
/dev/hda2       3782    5862    2081   16715632+  83  Linux
/dev/hda3       5863    6227     365    2931862+   5  Extended
/dev/hda4       6228    6835     608    4883760   83  Linux
/dev/hda5       5863+   6227     365-   2931831   82  Linux swap / Solaris

Disk /dev/sda: 12161 cylinders, 255 heads, 63 sectors/track
Warning: The partition table looks like it was made
  for C/H/S=*/16/63 (instead of 12161/255/63).
For this listing I'll assume that geometry.
Units = cylinders of 516096 bytes, blocks of 1024 bytes, counting from 0

   Device Boot Start     End   #cyls    #blocks   Id  System
/dev/sda1   *      0+ 193819  193820-  97685248+   b  W95 FAT32
                end: (c,h,s) expected (1023,15,63) found (1021,15,63)
/dev/sda2          0       -       0          0    0  Empty
/dev/sda3          0       -       0          0    0  Empty
/dev/sda4          0       -       0          0    0  Empty
larry at ldesk:~$


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