From this link, you will see that the main features of the memory required for the board to work fine are:
- Four 240-pin Double Data Rate 2 (DDR2) SDRAM Dual Inline Memory Module (DIMM) connectors with gold-plated contacts
- Non-ECC, 1.8 V, DDR2 800/667 MHz memory
- Serial Presence Detect (SPD) memory only
- Unbuffered, non-registered single- or double-sided DIMMs (except double-sided DIMMs with x16 organization)
- Up to 2.0 GB utilizing 256 Mb technology
- Up to 4.0 GB utilizing 512 Mb or 1 Gb technology
- Up to 8.0 GB utilizing 1 Gb technology
- A minimum of 512 MB of total memory is required
Note that: 2.1V memory modules are not supported, even though that it is working fine, it may be a problem in the future and this vois warranty when using non-recommended memory modules.
Also note that Intel does have a tested list for memory module, it is best to go for these modules in the future.
So now in your case, the best thing to do is to get memory of the same features that meet the above requirements.
All the best,