exec/passthru on WinNT

Running PHP4.0.2 & 4.0.1pl2.. It seems when I use exec and passthru under winnt to use cmd-line compressors such as arj/lha/rar and zip the exec function halts and waits for a keypress, sometimes it even hangs after that. works just fine in win98. i.e.: passthru("arj e -y -hf2 test.arj c:\\temp"); the lha equivalent: passthru("lha e test.lzh c:\temp\") makes the prompt hang. Can someone confirm this and know of a workaround/fix?