clock format puzzle

1. testcase:

1.1 code:

set ptime [palmtime from $sometime]
puts [format 0x%08x $ptime]
puts [clock format $ptime]

1.2 output:

C:\src\tclplkr>tclkitsh85 clock.tcl
0x44f5c9ee
Wed Aug 30 21:25:02 +0400 2006

2. actual project:

2.1 code:
puts [format 0x%08x $header(creationDate)]
set header(creationDate) [clock format $header(creationDate)]

2.2 output:

C:\src\tclplkr>tclkitsh85 unpluck.tcl modsecman.pdb
0x44f5c9ee
number too large to represent as a Posix time
    while executing
"GetDateFields $clockval  $TZData($timezone)  2299161"
    (procedure "::tcl::clock::formatproc'%a %b %d %H:%M:%S %Z %Y'C" line 4)
    invoked from within
"$formatter $clockval $timezone"
    (procedure "::tcl::clock::format" line 74)
    invoked from within
"clock format $header(creationDate)"
    invoked from within
"set foo [clock format $header(creationDate)]"
    (file "unpluck.tcl" line 251)

As you can see, the actual value passed to [clock format] appears to be the same integer.