Strange Parser error

I have been working on a script and come to a brick wall which I can't break... I am using Suse Linux 2.2 kernel, PHP4.04pl1 Mysql 3.22 Mod_ssl open_ssl - this is running on an old 486 with 16Meg RAM. I have a session object variable ($Items) which has as one of its elements ($LineItems) an array of objects each containing the order line details. This script is to insert the records to process a dispatch into an invoice. I lock (all the tables I need to lock) before going into a loop through all the $Items->LineItems and then a whole raft of SQL inserts and updates using the same $SQL variable to hold the SQL and $Result variable to hold the result in each case. The problem is that I get a parser error when the sript within the foreach ($Items->LineItems as OrderLine) loop gets too big when I remove the last block of code the pasrser error which was occurring at a line before the deleted code dissappears and the script works (as far as it goes). Add in a few more lines within the loop and the parser error comes back but further up in the code that was previously working ok - and has not been changed!! The script is not huge line 343 - 385 is where the parser is falling over . Has any one hit this snag. I can post the script if this pricks anyones interest! TIA Phil Daintree