600XL Odd Booting Problem

Installed UAV video mod and upgraded the stock memory from 16K to 64K with the great Lotharek SRAM v3 64K module. All tests pass perfectly, memory test passes perfectly, sound test and keyboard test perfect. Odd issue is when it boots up its not like the traditional A8 boot up. Also when I insert cartridge games it works for a while then locks up or crashes. Should I back track and go stock to narrow the problem?