ebaobao: EPA is commercial product really you should ask your question on the authors forum as EPA will be written differently to EP 1.2.5.4. As I understand that it is not a open source module.

overmyhead: How many products have you ? The thing with hosting if you buy a shared hosting package there may be 2000 other sites on that server, and you will only be allowed x amount of memory/ram if other sites are v busy they will take the power at the expence of yours.

ORIKO : This may be a permission error, is your temp folder permission set currently ?
Reading your error you are receiving it is not seeing this file ? Also check your files, have you been altering any files ?
PHP Code:
No such file or directory