bug in the display mechanism of the ms macros

[Y T]

GROFF VERSION: 1.19.2

MACHINE: P4 PC

OS: Linux, Redhat 9

COMPILER: g++ 3.2.2

INPUT FILES:
------------------------------------------------------------
.LP
This is a test.
.DS B
.IP 1)
Line 1
.IP 2)
Line 2
.DE
.LP
End of test.
------------------------------------------------------------

COMMAND LINE: groff -ms foo > foo.ps

DESCRIPTION OF INCORRECT BEHAVIOUR:

It seems that the display mechanism is broken in the ms macro package.
Any LP/IP within the display seems to terminate the display.
So, if foo is the example above (without the horizontal lines),
the result is:
foo:4: macro error: automatically terminating display
foo:8: macro error: DE without DS, ID, CD, LD or BD

The example above works fine with the traditional ms macros.
Not being able to use LP/IP within a display is a major problem.